In Pixar's Cars (2006), Doc Hudson reveals that he once drove for the Fabulous Hudson Hornet team.
Doc is introduced as the stern judge of Radiator Springs, but he is secretly a former champion racer. He competed as the Fabulous Hudson Hornet, winning three Piston Cups and establishing a reputation as one of the sport's greatest drivers. A crash ended his racing career, and the racing community quickly moved on without giving him the respect he felt he deserved.
His history explains why Doc reacts so strongly to McQueen's careless attitude. He recognizes the young car's talent but distrusts fame that is not supported by loyalty or humility. After initially refusing to help McQueen, Doc eventually trains him and becomes an important mentor.
Doc Hudson is voiced by Paul Newman, whose performance was one of the film's major attractions. The character is based on the real Hudson Hornet, a distinctive early-1950s American car associated with successful stock-car racing. The Fabulous Hudson Hornet name therefore connects fictional biography with automotive history.