Power. Space. Comfort. Prestige. These are traits that well-heeled luxury car buyers demand from their vehicles. They want something that provides a rewarding driving experience, but at the same time coddles them in executive-jet comfort.

These cars might not be a brand's best-selling vehicle, but automakers still understand the need to offer a premium large car to help satisfy the tastes of the most discerning buyers. Consumer Guide identifies nine models in this class from such nameplates such as Audi, BMW, Cadillac, Infiniti, Jaguar, Lexus, Lincoln, Mercedes-Benz, Volkswagen, and Volvo.

Note that for 2007, the Infiniti Q45 and Volkswagen Phaeton have been discontinued. Redesigned for '07 are the Lexus LS, Mercedes-Benz CL-Class and S-Class, and Volvo S80.

Large and In Charge
These cars are stately in power, interior space, and luxury touches. All in this class are available with V8 engines. Audi's new S8 is a sporty A8 and has a V10. A few, including the Audi A8, BMW 7-Series, and Mercedes-Benz CL-Class and S-Class are available with V12s.

Many premium large cars accelerate like sporty coupes. In Consumer Guide tests, the V8 versions of these cars typically do 0-60 mph in less than 7.0 seconds. Mercedes-Benz says its V12 S600 will make the same run in 4.5 seconds. To put that in perspective, Porsche pegs its sporty 911 Carrera S coupe at 4.6 seconds.

All cars in this class use an automatic transmission. The Cadillac DTS and Lincoln Town Car make do with a comparatively pedestrian four-speed. No five-speed transmissions are available in this class, making six-speeds the most common. Mercedes' entries have a seven-speed automatic. Not to be outdone, Lexus' new LS 460 has an astonishing eight-speed automatic.

Big Outside, Big Inside
Some manufacturers offer versions of their premium large cars with extended wheelbases, which allow for more room and comfort, especially in the rear seat.

The Audi A8, BMW 7-Series, Jaguar XJ8, Lexus LS, and Lincoln Town Car are available with long wheelbases. While a typical midsize sedan has about 35 to 37 inches of rear leg room, the A8 L, 7-Series Li, XJ8L, LS L, and Town Car L offer between 39.3 and a limousine-like 45.4 inches of space to stretch your legs. Don't dismiss other cars in this class, though. The Cadillac DTS has 41.6 inches of rear leg room, and the Mercedes S-Class has 42.3. Front-seat occupants are also treated to expansive room, with the Lexus LS leading the pack at 43.7 inches of leg room, with the Cadillac DTS closely behind at 42.5.

Cargo capacity varies greatly, from 21.0 cubic feet in the Lincoln Town Car, down to 12.3 in the Mercedes CL-Class. Keep in mind, though, the Benz is a 2-door coupe. The smallest trunk among four-door sedans is the Audi A8 at 14.6 cubic feet.

Brimming with Safety and Luxury Features
Buyers of premium large cars demand the best, and automakers go all out to try and satisfy those needs, which include plenty of high-tech safety, comfort, and convenience features.

ABS, traction control, antiskid system, and curtain side airbags are expected safety features and standard across the board. The Lexus LS and Mercedes S-Class have added electronics that can sense an impending collision and respond by tightening the seat belts and applying additional braking force.

While most premium large cars are rear-wheel drive, the A8 comes standard with Audi's quattro all-wheel drive. AWD is also available on the Mercedes S550 and Volvo S80. The S80 can be had with front-wheel drive also, and this is the only way Cadillac offers the DTS.

Most models offer front and/or rear obstacle detection systems. Bumper mounted sensors detect when objects are too close and sound audible alerts. Some add a rearview camera that uses available navigation systems to display an image of what's behind the vehicle with the transmission in reverse. The S-Class has an optional night vision system that uses infrared lighting to project a highlighted image of distant objects that might not be visible otherwise.

Inside, opulence is the name of the game. Leather upholstery, dual front and rear automatic climate control, and high-end audio systems are among many available features for these cars. DTS, LS, and S-Class offer cooling front seats with a massaging function.

Once on the road, many premium large cars are available with adaptive cruise control, which uses sensors to detect vehicles up ahead and slow down the car automatically if it gets too close. The S-Class' Distronic system can completely stop the car if necessary, though such a feature requires placing your faith in technology.

Speaking of faith in technology, the Lexus LS has a feature it calls the Advanced Parking Guidance System. It's designed to automatically parallel park the car by using a combination of the navigation, obstacle detection, and steering systems, all aided by the rearview camera. It's an interesting piece of technology, but it takes a long time to program and is certainly not necessary if you're already good at parallel parking.

Luxury's Price Tag
All these comfort and luxury features don't come cheap. While some models can be had for as little as $45,000, others easily double, and in some cases, triple that figure. The A8, 7-Series, CL-Class, and S-Class all have models with base prices greater than $100,000.

Consumer Guide chose the Mercedes-Benz S-Class as a Best Buy among premium large cars. The Audi A8 and Cadillac DTS earned our Recommended label. If you're lucky enough to be able to afford one of these cars, you'll be treated to something powerful, luxurious, and comfortable. And for many, these things are something that can't have a price tag put on them.

Audi A8 Base Price Range: $68,900-$119,350 EPA MPG Range: 15-25 Body Style: 4-door sedan Audi trails BMW, Lexus, and Mercedes-Benz for prestige and resale value, but it's closing the gap. Its flagship A8 trumps rivals for interior decor, standard all-wheel drive, and, depending on model, base price. A8s can overwhelm with high technology, and the air suspension doesn't provide an ideal ride/handling balance, but these are formidable premium large sedans by any measure, and Recommended picks in this class.

BMW 7-Series Base Price Range: $75,000-$121,400 EPA MPG Range: 14-25 Body Style: 4-door sedan Smooth, powerful, and athletic, the 7-Series has precious few dynamic flaws. It's also spacious and very comfortable--true first-class travel. Workmanship matches the lofty pricing, but BMW's i-Drive control makes many simple adjustments frustratingly complex.

Cadillac DTS Base Price Range: $41,390-$48,760 EPA MPG Range: 17-25 Body Style: 4-door sedan Cadillac leaves any sporting pretensions to its rear- and all-wheel-drive STS models. The front-drive DTS aims for the traditional American-luxury-car buyer, and scores. It's powerful, roomy, and refined, and matches most rivals for standard safety features. Starting in the low-to-mid $40,000s, the base and Luxury I versions are particularly strong Recommended values.

Jaguar XJ Series Base Price Range: $63,585-$91,335 EPA MPG Range: 17-27 Body Style: 4-door sedan Ford owns Jaguar, and the British marque's special character feels watered down in the XJ. Still, this is a solid enough luxury sedan. The basic XJ8 versions are the best value within this lineup. Though most XJ models tend to undercut most rivals on price, they don't match the resale values of Lexus and Mercedes-Benz rivals.

Lexus LS Base Price: $61,000-$71,000 EPA MPG Range: 19-27 Body Style: 4-door sedan Full prices were unavailable in time for this report, but LS base prices start below those of the Mercedes-Benz S-Class and Audi A8. It is less sporty and more comfort oriented than those German rivals, but is outstanding in its own right in terms of power, refinement, expected standard features, and optional gadgets.

Lincoln Town Car Base Price Range: $42,115-$50,585 EPA MPG Range: 17-25 Body Style: 4-door sedan Town Car blends old-school American luxury, space, and isolation with surprisingly good road manners, all things considered. Cadillac's rival DTS is a far newer design with better performance and handling, but this elderly Lincoln still makes sense to some buyers.

Mercedes-Benz CL-Class Base Price Range: $99,900-$144,200 EPA MPG Range: 12-24 Body Style: 2-door coupe We have not yet tested the 2007 Mercedes-Benz CL-Class.

Mercedes-Benz S-Class Base Price Range: $85,400-$181,500 EPA MPG Range: 12-24 Body Style: 4-door sedan The S-Class defines luxury motoring. Encompassing serenity and inspiring road manners are its hallmarks. Unfortunately, cars of this caliber also force the driver to interact with diversionary hi-tech features, many of which require far too many steps to adjust. In that regard, S-Class runs with the pack. Our Best Buy pick here is the S550. It delivers such high levels of performance and luxury that it is difficult to justify $55,000 more for the S600.

Volvo S80 Base Price Range: $38,705-$47,350 EPA MPG Range: N/A Body Style: 4-door sedan Volvo's redesigned S80 is stylish and comfortable, but it can't match the brand cache and the sportiness or pure luxury of the best in this class. Six-cylinder versions trail rivals for power and aren't offered with all-wheel drive. V8 versions are more in line with luxury buyers' expectations and their prices undercut V8-powered competitors.