Doc Hudson becomes Lightning McQueen's new crew chief in Pixar's Cars.
Doc initially appears to be the gruff judge of Radiator Springs, but Lightning learns that he was once a celebrated racer. Known as the Hudson Hornet, Doc won three Piston Cups before a crash ended his competitive career and left him feeling forgotten by the racing world.
After seeing McQueen's talent and selfishness change, Doc returns to the racetrack as his crew chief. He organizes the Radiator Springs residents as McQueen's pit crew for the decisive race. Doc's return is important because it reconnects him with racing while giving McQueen the mentorship he lacks.
Doc is voiced by Paul Newman, whose own association with racing added resonance to the role. The character is based on the real Hudson Hornet, a famous early-1950s stock car, but Doc himself is a fictional character within the Cars universe.