The Used Car Rule, formally known as the Used Motor Vehicle Trade Regulation Rule, has been in effect since 1985. It requires car dealers to display a window sticker, known as a Buyers Guide, on the used cars they offer for sale. The Buyers Guide discloses whether the dealer offers a warranty and, if so, its terms and conditions, including the duration of the coverage, the percentage of total repair costs the dealer will pay, and which vehicle systems the warranty covers. In states that do not permit sales of used cars “as is,” or without warranties, dealers must display an alternative version of the Buyers Guide.
For more information, see https://www.ftc.gov/enforcement/rules/rulemaking-regulatory-reform-proceedings/used-car-rule