In Pixar's Cars, Doc Hudson gives Lightning McQueen advice in Radiator Springs.
Doc initially presents himself as the town's judge and doctor, but McQueen discovers that he was once a celebrated race car. Doc won three Piston Cups and held the record for most wins in a single season before a serious crash ended his racing career.
Paul Newman voices Doc Hudson in Cars. Newman was an acclaimed actor and also a successful professional racing competitor, so the role connected the character with a performer who understood both celebrity and motorsport.
Doc's experience helps McQueen understand that winning is not the only measure of a racing life. The character is modeled after the Hudson Hornet, a real American car associated with the early 1950s and with success in stock-car racing. Doc's past is a major reason McQueen changes by the film's conclusion.