Alll new cars sold in the U.S. must have posted on a side window what is often called a "Monroney sticker" (named for the congressman who introduced the legislation). This law does not apply to light trucks, including passenger vans and most sport-utility vehicles, but most car companies and dealers voluntarily put price stickers on trucks.

The Monroney sticker must show:

The manufacturer's suggested retail price (MSRP) for the vehicle and all of its factory-installed options.
A destination charge for shipping from the final assembly point or port of importation to your local dealership, which is added to the MSRP to produce a Total Price.
EPA fuel economy estimates.
Parts Content Information.
Additional information generally is supplied, including lists of standard and optional equipment.

Many dealers add a second window sticker that lists accessories installed at the dealership, and/or other charges. Everything on this added sticker should be considered "optional" and arguable. More than likely, these items are overpriced as well as nonessential. If you don't want a particular item -- for instance, pinstriping or paint sealant -- don't pay for it. If the dealer insists that it is already on the car, you can still refuse to pay.

These add-on stickers typically include high-profit (and unnecessary) rustproofing and protection packages. Some denote charges like M.V.A., A.D.P., or other cryptic abbreviations. These are nearly always smoke screens for dealer-invented profit-generators. M.V.A. stands for "Market Value Adjustment," and A.D.P. is "Additional Dealer Profit." Both sound official, but they're created by dealers to squeeze more money out of you.

Some dealers dream up dandy new names for old add-on charges, such as "Currency Valuation Fee" and "Import Tariff." It is in your best interest to avoid dealers that engage in these unsavory practices.

Used cars at a dealership must have a completely different window sticker posted. The Used Car Rule, exercised by the Federal Trade Commission, requires that a Buyers Guide be easily visible from outside the car. In addition to basic vehicle information, the Buyers Guide must show:

Whether the vehicle is offered "as is" or with a warranty.
Warranty details, if included with the vehicle.
What percentage of the repair costs a dealer will pay under warranty. In most used-car warranties, the dealer and owner split the cost of repairs according to a predetermined percentage.

The Buyers Guide also tells consumers that oral promises are difficult to enforce, recommends that all promises should be written, and suggests that the car be inspected by an independent mechanic before purchase. On the reverse side of the Buyers Guide is a list of defects that a used vehicle might have.