In Pixar's Cars, retired racer Doc Hudson becomes Lightning McQueen's crew chief.
Doc initially appears to be the judge who sentences Lightning to repair Radiator Springs' damaged road. He later reveals that he once raced as the Fabulous Hudson Hornet and won three Piston Cups. His racing career ended after a serious crash and after he felt forgotten by the racing world.
Doc's knowledge helps Lightning improve his driving, especially on the difficult dirt roads around Radiator Springs. The former champion becomes a mentor, although he keeps his own racing history secret from much of the town. Near the end, Doc accepts a new role with Lightning's team and joins him at the Piston Cup race.
Sally Carrera serves as Lightning's romantic partner, while Sheriff enforces the town's rules. Neither is Lightning's crew chief. Doc Hudson is the character who combines veteran racing experience with the mentoring role.