The FTC requires car dealers to use display a window sticker, known as a Buyers Guide, on the used cars that they offer for sale.The Buyers Guide tells whether the dealer offers a warranty and, if so its terms and conditions, including the length of the coverage, the amount of total repair costs the dealer will pay, and what vehicle systems the warranty covers. In states that don't permit sales of used cars “as is,” or without warranties, dealers must display an alternative version of the Buyers Guide.