Wherever there are cars, there are people who try to squeeze every last bit of performance out of them. Often times, they will turn to aftermarket parts and accessories to increase horsepower and improve handling.

There are people who want better performance than "standard" models, yet may not have the technical expertise to do modifications themselves or want to risk voiding the warranty. In these cases, several automakers offer cars that come tuned straight from the factory. Such vehicles are available in different sizes, body styles, and prices.

Factory-tuned compacts like the Honda Civic Si or Chevrolet Cobalt SS Supercharged can be had for about $20,000. The midsize MazdaSpeed 6 sedan is about $30,000. The full-size Dodge Magnum SRT-8 wagon is about $40,000. Going all the way up the price ladder, the supercharged Cadillac XLR-V convertible and Porsche 911 GT3 coupe break six figures.

The Subaru Impreza WRX STi (bottom) adds more horsepower, sportier suspension, 6-speed manual transmission, uprated brakes, and front and center limited-slip differentials to the base Impreza (top).

In this first of a three-part series, we'll look at factory-tuned performance cars from various manufacturers with starting prices of less than $30,000. These cars show that driving fun doesn't necessarily have to break the bank.

From Overseas
Import-brand cars like the Honda Civic Si and Volkswagen GTI are favorites among the factory-built, high-performance crowd.

The Civic Si takes a standard Civic coupe (or new-for-2007 sedan), and substitutes its 140-horsepower 1.8-liter 4-cyl engine for a 197-horsepower 2.0-liter. The GTI ditches the base Rabbit's 150-horsepower 5-cyl engine in favor of a 200-horsepower turbocharged 4-cyl. Standard 17-inch tires, sport suspension, and 6-speed manual transmissions on both up the performance ante versus their more basic counterparts. The Civic Si starts at $19,990; the GTI at $21,990.

For $23,065, the GTI can be had with Volkswagen's 6-speed Direct Shift Gearbox (DSG). The DSG is a sequential manual transmission, which is essentially a manual transmission without a clutch pedal. Shifting is done via steering wheel paddles or the floorshifter. It can also be set to shift like an automatic.

Other entries include tuned versions of the compact Subaru Impreza sedans and wagons. Though available in the United States only since 2001, the WRX traces its roots back to 1992. It owes much of its heritage to rally racing. Street versions have standard all-wheel drive, a 230-horsepower turbocharged 4-cyl engine, and manual or automatic transmission. Compare that to a 173-horsepower 4-cyl found in base Imprezas. The WRX TR sedan starts at $23,995; the Limited wagon at $26,995.

If that's not enough, Subaru has the $32,995 WRX Sti. This sedan boosts standard WRX horsepower to 300. It also has a 6-speed manual transmission versus other WRX's 5-speed. A sportier suspension, uprated brakes, and front and center limited-slip differentials are also included.

Mazda's midsize 6 sedan has a performance version. The MazdaSpeed 6 supplants a 215-horsepower 3.0-liter V6 with a 274-horsepower 2.3-liter turbocharged 4-cyl engine. It has a starting price of $27,995 for the Sport version. The Grand Touring bumps its head on the $30,000 mark with a starting price of $29,925. That extra money buys leather upholstery, heated front seats, and keyless access and starting.

Later this fall, Mazda will launch a tuned version of its compact 3 sedan. The MazdaSpeed 3 will have the same 2.3-liter turbocharged 4-cyl engine that the MazdaSpeed 6 sedan and CX-7 SUV have, but according to Mazda, its output will be tuned to "more than 250 hp." A 6-speed manual transmission will be standard, as will 18-inch tires.

The Dodge Caliber SRT4 (bottom) will have a 300-horsepower turbocharged 2.4-liter 4-cyl engine. The base model (top) has a 148-horsepower 1.8-liter 4-cylinder engine.

While it's not much more powerful than other V6 versions, Nissan's Altima SE-R brings other enhancements to this midsize sedan lineup. SE-R versions have a 260-horsepower 3.5-liter V6 engine with a 6-speed manual or 5-speed automatic transmission. Other V6 Altimas have 250 horsepower and manual or automatic transmissions with five speeds. The $29,650 SE-R has specific suspension and exhaust tuning, a rear spoiler, and performance 18-inch tires instead of the standard 16s.

From America
Though imports tend to be favored in tuner circles, don't count out the domestics. General Motors sells performance-oriented versions of its compact Chevrolet Cobalt and similar Saturn Ion. The Cobalt SS Supercharged and Ion Red Line are coupes that have a supercharged 205-horsepower 2.0-liter 4-cyl engine and 5-speed manual transmission. This marks a 60-horsepower gain over base versions of these cars. The Cobalt SS Supercharged starts at $19,900; the Ion Red Line at $19,625.

GM recently launched "Stage One" and "Stage Two" performance kits for the SS Supercharged and Ion Red Line. Stage One kits cost $500 and include high-flow fuel injectors and revised engine programming to boost horsepower to 236. Stage Two adds a smaller supercharger pulley and drive belt for 241 hp total. The kits are available at Chevrolet and Saturn dealerships, and are backed by a factory warranty.

Also part of the GM stable are the Pontiac Solstice GXP and its corporate cousin, the Saturn Sky Red Line. These rear-wheel drive, two-seat convertibles are new for 2007, supplementing the base 177-horsepower versions. GXP and Red Line have a 260-horsepower turbocharged 2.0-liter 4-cyl engine and a 5-speed manual transmission. They also have GM's Stabilitrak antiskid control, which is unavailable on the base models. Solstice GXP starts at $25,395; the Sky Red Line at $27,295.

The Chrysler Group has its own special consortium of factory tuners. Dubbed the Street and Racing Technology group, this team of engineers flexes its muscle by tweaking existing Dodge, Chrysler, and Jeep products with high-power engines and other upgrades.

Due in spring 2007, Dodge will offer an SRT version of its compact Caliber wagon. The SRT4 will have a 300-horsepower turbocharged 2.4-liter 4-cyl. Dodge estimates 0-60 acceleration at less than 6 sec. The current top-line Caliber R/T has 172 horsepower, with an estimated 0-60 time of 10.8 sec. Pricing isn't available yet, but it's expected to start at around $21,000.

Part two of this series will focus on factory-tuned performance cars with a starting price between $30,000 and $50,000.

In the first installment of this series, we took a look at cars that received high-performance treatment right at the factory and had starting prices of less than $30,000. Moving up to the $30,000 and $50,000 bracket, domestic and import automakers offer some really potent performance machines.

From America
This time we'll start with a look at the horses in the domestic stable, starting with Chrysler and Dodge.

Chrysler's 300 sedan and Dodge's Charger sedan and Magnum wagon can take a trip through the company's Street and Racing Technology (SRT) finishing school. When they've graduated, each emerges as the 300, Charger, and Magnum SRT8. Instead of a 190 and 250-horsepower V6 engine, or a 340-horsepower 5.7-liter Hemi V8, these performance models have a 425-horsepower 6.1-liter Hemi V8.

Top: The 2007 Ford Mustang GT. Bottom: The Shelby Mustang GT500 goes from 0-60 in 5.2 seconds.

Chrysler pegs any SRT8 at around 5.0 seconds 0-60 mph, and that's with a standard 5-speed automatic transmission. Sadly, no manual transmission is available. All seat five, and the Magnum can do this, or haul up to 71.6 cu-ft of cargo. Not too many 400 horsepower cars can claim that. The 300 SRT8 starts at $39,920, the Charger at $35,320, and the Magnum at $37,320.

General Motors takes a bit of a different approach to factory-tuned performance in this price range. While the 300, Charger, and Magnum are large, rear-wheel drive cars, GM looks to its front-drive midsize sedans. Enter the Chevrolet Impala SS and Pontiac Grand Prix GXP.

These sedans share their basic underskin design, but the SS and GXP are the only two versions that share engines. In this case, GM installs a 303-horsepower 5.3-liter V8. These sedans are among the most powerful front-drive cars sold in North America. The engine also has GM's Active Fuel Management system that shuts off four cylinders while cruising to save fuel. Both cars use a 4-speed automatic transmission.

The problem with putting this much power through the front wheels is managing torque steer, a condition that causes the car to pull to the side during hard acceleration. Pontiac tries to compensate for this condition by giving the GXP tires that are larger up front than in the rear. Impala's tires are the same size all around.

Traditionalists will balk at the idea of an American car company putting a powerful V8 engine in a front-drive car. But there's no denying that these performance cars are interesting choices with reasonable pricing. The Impala SS starts at $27,780, the Grand Prix GXP at $28,560.

Note that Chevy also sells the Monte Carlo SS, which is essentially a 2-dr Impala with the same engine. It's the only domestic-branded midsize coupe. Also, rumor has it that Buick will offer its LaCrosse sedan (which also shares some platform parts with Impala and Grand Prix) with the V8.

The last Motown motor manufacturer, Ford, has shied away from factory-tuned performance cars over the last decade. This Dearborn, Michigan-based automaker produced compact Focus and Contour cars, as well as F-150 Lightning pickups tuned by its Special Vehicle Team (SVT). Though they may have been relatively quiet in the performance department in recent years, the engineers in this division recently unleashed the 2007 Shelby Mustang GT500.

A spiritual successor to the Shelby Mustang GTs of the late 1960s (you may remember "Eleanor", the 1967 GT500 from the movie Gone in 60 Seconds), the '07 version is one of the most powerful vehicles Ford has ever produced. A supercharged 5.4-liter V8 engine produces 500 horsepower in this application. The only transmission is a 6-speed manual.

Top: The Mitsubishi Lancer ES. Bottom: The Mitsubishi Lancer Evo MR.

Acceleration checks in at 5.2 sec 0-60 mph, according to Ford's conservative estimate. GT500s are available as 2-door coupes or convertibles. Officials are optimistic that the coupe's $40,930 and the convertible's $45,755 starting points will appeal to those wanting near-exotic car levels of performance without completely breaking the bank.

From Japan
In part one of this series, we discussed Subaru and the turbocharged WRX versions of its Impreza sedan and wagon. On top of that, is the super-high-performance WRX STi, with 300 horsepower.

Rival Mitsubishi juices up its compact Lancer sedan to create the Evolution. Like the WRX, "Evos" were only available in Japan for many years. The 2006 roster includes the RS, newly introduced SE, IX, and MR. All have a 286-horsepower 2.0-liter turbocharged 4-cyl engine. Evo MRs have a 6-speed manual transmission, and the others use a 5-speed.

Acceleration of these sedans rivals top performance cars, at 5.5 seconds 0-60 mph. Handling also ranks very high, with Evo's standard all-wheel drive. They also have a switch that can lock the differentials for driving on the track or in the snow.

The Evolution RS is basic in every sense of the word. It doesn't have power windows, power locks, antilock brakes, or a radio. Air conditioning wasn't available on 2004 models, though it became standard in '05. All those deletions are designed to save weight. To further shed the pounds, the RS has an aluminum roof. The Evo IX has a steel roof, and adds those missing convenience features. It's also available with leather upholstery and a sunroof. SE and MR have the RS's aluminum roof. Both also have specific wheels and exterior trim.

Pricing is as follows: RS starts at $28,679, IX at $31,399, SE at $33,249, and MR at $35,189.

From Europe
Volvo's image traditionally has been that of safety, rather than performance. That doesn't mean a few tuned models can't make their way out of their factory in Sweden. Enter the S60 R sedan and V70 R wagon.

These premium midsize cars have a turbocharged 300-horsepower 5-cyl engine and all-wheel drive. Standard S60s and V70s have 5-cyl engines with 168, 208, or 257 horsepower. Rs have a standard 6-speed manual transmission or an optional 6-speed automatic. This powertrain combines for estimated 0-60 mph acceleration times of 5.4 seconds with the manual and 6.6-7.2 with the automatic.

S60 and V70 R have Volvo's Continuously Controlled Chassis Concept (Four-C) suspension with driver-selectable settings to emphasize ride quality or handling response. The S60 R can be had with 18-inch wheels; the V70 has 17s.

Sedan versions have a starting price of $37,920, and wagons start at $39,545.

The final installment of this series on factory-tuned performance cars will look at the absolute cream of the crop, where you'll find some of the finest examples of automotive technology--those cars with prices greater than $50,00

To this point, we've worked our way through various versions of production cars that receive special tuning from the factory. From compact pocket rockets such as the Chevrolet Cobalt SS Supercharged to the burly Dodge Charger SRT8, this series has covered vehicles with prices up to $50,000.

While there are some mighty fine rides in that group, we would be remiss not to go any higher on the price spectrum. The cars with sticker prices above $50,000 are truly the cream of the high-performance crop. Though not designed to be sales leaders, high-end factory-tuned cars give manufacturers a "halo" vehicle, the kind most people only dream of owning.

From Europe
Audi is launching high performance versions of its compact A4, midsize A6, and large A8 sedans. While the company already has S4 sedans and Avant wagons with a 340-horsepower 4.2-liter V8 engine, Audi is taking the sedan a step further by releasing the RS 4 quattro. It's still a 4.2-liter V8, but this version packs 420 horsepower. Major props go to Audi for creating an engine with more than 100 horsepower per liter that doesn't rely on a turbocharger or supercharger.

Top: '07 Audi RS 4. Bottom left: '07 Audi S6. Bottom right: '07 Audi S8.

A 6-speed manual transmission and Audi's quattro all-wheel drive get all that power to the pavement. RS 4 is capable, according to Audi, of 4.6 seconds 0-60 mph acceleration. The RS 4 starts at $66,000.

Coming to North American shores later in 2006 are the S6 and S8 sedans. Based on the A6 and A8, respectively, the S6 and S8 go beyond their "normal" siblings by swapping out V6 and V8 engines for V10s. S6 will have 420 horsepower, and S8 will have 450. The engine borrows many components from the V10 found in the Gallardo coupe from Audi-owned Lamborghini. Pricing isn't available yet, but expect S6 to come in well over $75,000. S8 should check in at over $100,000, but less than the Gallardo's $175,000 asking price. That's big savings, which can be put to use towards a yacht or heck, another factory-tuned performance car.

Fellow German automaker BMW also has a roster of performance machines. Like Mercedes-Benz, BMW has a separate arm dedicated to taking the company's stock cars and transforming them, all while retaining a factory warranty. These cars leave their factories in Germany and the United States with the M designation. M is short for M-Technik (though it could just as easily stand for Muscular) and was initially created to support the company's racing efforts. The 3-Series, 5-Series, 6-Series, and Z4 models are all recipients of the M group's engineering wizardry.

The M3 premium compact coupe and convertible are being phased out right now. They're based on a design from 1999 and have a 333-horsepower inline 6-cyl engine mated to a 6-speed manual or 6-speed sequential manual transmission (SMT). BMW redesigned its 3-Series coupes and convertibles for 2007 and has not announced plans to offer an M3. The M3 coupes start at $48,900, the convertible at $56,600.

The premium midsize M5 sedan substitutes a 500-horsepower V10 engine in place of standard inline 6-cylinders or V8s. It teams with a 7-speed SMT and has a starting price of $81,200. BMW also put this engine into its large 6-Series premium coupe to create the M6. It also has a 7-speed SMT and is priced northward of the M5 at $96,100. The company recently announced plans to build an M6 convertible. Pricing isn't available, but expect it to start above $100,000.

Midyear 2006 saw the reintroduction of BMW's American-built Z4 M convertibles and hatchback coupes. These sporty two-seaters have freshened styling and more power versus their predecessors. While all Z4 models have inline 6-cyl engines, M versions have 330 horsepower, which is 75 more than the next most powerful version. A 6-speed manual is the only transmission. The M hatchback starts at $49,300, with the convertible slightly more at $51,995.

Continuing on this trip through Deutschland, Mercedes-Benz has many factory-tuned performance cars in its stable. Nearly all of its cars and SUVs are available with the AMG designation.

AMG is the Mercedes performance arm. This division was formed 38 years ago as an independent tuner of Mercedes vehicles. The 1995 C36, a 268-horsepower V6 version of the compact C-Class sedan, was the first car sold in the U.S. under official agreement between Mercedes-Benz and AMG.

In subsequent years, the AMG-tuned C-Class outgrew its V6 and 4-speed automatic transmission. The current model is called C55 and has a 362-horsepower 5.4-liter V8 and a 5-speed automatic. It also adds standard 18-inch tires vs. 17s on other C-Classes, as well as uprated suspension tuning and brakes. The C55 has a starting price of $54,450. Ironically, C55 is discontinued for 2007, making the C-Class the only model in Mercedes' lineup without an AMG-tuned version.

AMG's influence continues to spread through the rest of Mercedes' product portfolio. In the past, they simply picked cars off the assembly line and tweaked them. For 2007, AMG began building its own engines from scratch and dropping them into the appropriate vehicles. Add that to the other customizing AMG does; including specific tires and wheels, suspension tuning, brakes, and exterior and interior trim; and you have a fleet of vehicles that kick butt, as well as pamper it.

Mercedes' 2007 AMG lineup looks like this:

• CL-Class- Though Mercedes hasn't officially announced an AMG version of its top-line coupes for '07, '06 models should still be available. The CL55 has a 493-horsepower supercharged 5.4-liter V8 and a $125,000 base price. AMG shoves a 604-horsepower 6.0-liter turbocharged V12 under the hood of the CL65. Start saving your pocket change because the car will cost you $179,600.
• CLK-Class- The CLK63 is a 2-door convertible with a power fabric top and heated glass rear window. It has a 475-horsepower 6.2-liter V8 engine and 7-speed automatic transmission. Pricing isn't available, but expect it to be more than the $62,900 for the stock CLK550 convertible.
• CLS-Class- Essentially an E-Class sedan wrapped in different sheetmetal, the CLS63 will have a 507-horsepower 6.2-liter V8 engine. This replaces the '06 CLS55, which had a supercharged 469-horsepower 5.4-liter V8. Expect '07 versions to cost more than the $86,600 of the '06 CLS55.
• E-Class- Mercedes' restyled midsize sedans and wagons both get AMG treatment in the form of the E55. They share the 507-horsepower 6.2-liter V8 of the CLS-Class, as well as its 7-speed automatic. Though prices aren't available yet, they should cost more than the $81,800 for the 2006 E55 sedan and $82,600 for the E55 wagon.
• SLK-Class- The less costly of Mercedes' two-seat convertibles offers the SLK55 with AMG's tuning. Its 5.4-liter V8 produces 355 horsepower. Pricing for '07 is yet to be announced, but it shouldn't be much more than the '06 models' $61,500, a figure that's downright reasonable compared to the next two cars on this list.
• S-Class- AMG's engineers must have licked their chops when the revamed '07 S-Class sedan found its way into their labs. They took Mercedes' top-end sedan and outfitted it with a turbocharged 6.0-liter V12 engine that produces 604 horsepower, thus creating the S65. The V12's torque output is a curb-stomping 738 lb-ft. That's more than the combined torque ratings of the Chevrolet Aveo, Ford Focus, Honda Fit, Hyundai Accent, Nissan Versa, and Toyota Yaris. Mercedes says you can go from 0-60 mph in 4.2 seconds. What could go faster? How about the money from your bank account should you want to purchase one. This sedan will cost you $182,275.
• SL-Class- AMG versions of Mercedes' costliest two-seat convertibles carry over into '07, with the 510-horsepower supercharged 5.4-liter V8 SL55 and the 604-horsepower turbocharged 6.0-liter V12 SL65. Sticker prices are equally lofty, at $128,800 for the SL55 and a coronary-inducing $186,000 for the SL65.

Lastly, we roll out of Germany and into merry ol' England, where Jaguar produces its own line of premium factory-tuned performance cars. The British marquee gives its tuned cars the R designation. All of its models, except the compact X-Type can be had with this treatment.

Jaguar's midsize S-Type and large XJ Series sedans share their R-version engine, which is a supercharged 400-horsepower 4.2-liter V8. Combined with a 6-speed automatic transmission, the S-Type R is good for a 6.1 seconds 0-60 mph acceleration time, and you can expect the XJR to do about the same. In addition to engine modifications, Rs have specific suspensions, wheels, and tires to provide a sportier feel than their standard counterparts. Other visual enhancements include a wire-mesh grille. The S-Type R starts at $63,330, and the XJR will set you back $80,835.

Speaking of sporty, Jaguar just launched the R version of its redesigned '07 XK coupe and convertible. The XKR benefits from its siblings' all-aluminum construction and stiff frame. Like the S-Type and XJ, it too has a supercharged 4.2-liter V8, but XKR has 420 horsepower. Both coupe and convertible body styles will be available as Rs, and you can expect both versions to start well above their "base" counterparts' respective sticker prices of $74,835 and $80,835.

From Japan
While Japanese brands offer many different factory-tuned performance cars, they're all in the sub-$50,000 price range. That may change in the next 12 months, though, as rumors abound about Lexus offering the IS 500, a souped-up version of its premium compact sedan. The current top-end IS 350 has a 306-horsepower V6 engine, but the IS 500 would have a V8 with more than 400 horsepower. That would make the IS 500 the fastest production Toyota since the Supra Turbo of the 1990s. Stay tuned for further developments on this story.

From America
Like the Japanese, domestic automakers haven't dabbled much in the sciences of factory-tuned performance cars with sticker prices greater than $50,000. Chrysler doesn't have any models playing in this field (Viper doesn't count as it's a tuned model in and of itself), and there are no Fords, Lincolns, or Mercurys either. General Motors is the only automaker attempting to take on Europe's heaviest hitters with products built right in the U.S. of A.

Cadillac enters the fight with three different models, all of which carry the V designation. This lineup works just like BMW's M and Mercedes' AMG, and those German rivals are Cadillac's targets.

Top: '07 Cadillac CTS-V. Bottom: '07 Cadillac XLR-V.

First up is the CTS-V. Instead of tuning this model's 255-horsepower V6 engine with a turbocharger, supercharger, or revised internal components, Cadillac does the job with the brute force of good-old-fashioned American V8 muscle. The engine of choice is the Chevrolet Corvette's 400-horsepower 6.0-liter unit. Purists can take delight in the fact that the only available transmission is a 6-speed manual. CTS-V has unique styling cues, including a wire mesh grille, and 18-inch wheels on run-flat tires. With the BMW M3 and Mercedes C55 as its primary targets, CTS-V is priced accordingly at $50,770.

The larger STS-V positions itself as a rival to the BMW M5 and Mercedes E55. Though STS rides on a stretched version of the CTS architecture, GM tunes it much differently. STS-V has a V8 engine, but in this application it's a supercharged 469-horsepower 4.4-liter unit that teams with a 6-speed automatic transmission. It's the most powerful production Cadillac ever, and the company says it's capable of a 4.8-seconds 0-60 mph time. That may be a bit slower than the Bimmer or Benz, but STS-V is less expensive, with a base price of $74,445.

STS-V may be the most powerful production Cadillac, but the flagship XLR-V convertible is the most expensive. This two-seat convertible has a base price of $97,460. Add in a $1700 gas-guzzler tax and destination charge, and it's the first GM vehicle to have a six-figure sticker.

That price will get you a convertible that shares some of its platform with the Corvette, though obviously the two don't look anything alike, nor do they share engines. Like the STS-V, XLR-V has a supercharged 4.4-liter V8 engine and 6-speed automatic transmission.  The convertible has to make do with 443 horsepower, but Cadillac's claim of 0-60 mph acceleration at 4.6 seconds would make it faster than the STS.

And speaking of the Corvette, while the base models are fast in their own right (Chevy says 4.5-seconds 0-60 mph), they're still not the most powerful. Consider now the 2007 Corvette Z06. Instead of a 400-horsepower 6.0-liter V8 engine, Chevy drops in a 505-horsepower 7.0-liter V8. Sheer brute force propels this hot-rod 'Vette to an estimated 3.7-seconds 0-60 time. That's faster than many exotics with six-figure stickers. Not only does the Z06 cut down those cars on a straightaway, it also cuts them down on price. It starts at $69,175, which, among this entire crop of high-end factory performance cars, can be considered a bargain.

They're not cheap, but the lucky few who can pony up the Benjamins to get into these cars are virtually guaranteed smiles at every press of the pedal, flick of the gearshift, and turn of the steering whee