Under the Federal Trade Commission (FTC) Used Car Rule, All sellers of used cars (except private owners), are required to place a large sticker called a "Buyers Guide" in the window of their used cars, light-duty vans and light-duty trucks. The "Buyers Guide" will tell you whether the vehicle comes with a warranty and, if so which systems are covered, how long coverage applied, and what percent of repair cost the dealer will pay.
The Buyers Guide also alerts you when a car is being sold with "as is" which means with no warranty at all. The dealer has no further responsibility for a car sold "as is," once the sale is complete and you drive off the lot.
Typically, the Bureau suggests that you take the vehicle to you independent mechanic for an inspection prior to making a commitment to purchase. You may wish to check with a local bank or credit union concerning the "blue book" value of the vehicle to assist you in the negotiation of the price you pay for the vehicle.