In Pixar's Cars, Doc Hudson is revealed to have been a three-time Piston Cup champion.
Doc initially presents himself as Radiator Springs' local doctor and avoids discussing his racing past. McQueen eventually discovers that Doc was once the Fabulous Hudson Hornet, a celebrated racer whose career was cut short after a serious crash and a period of recovery.
The character is based on the real Hudson Hornet, a car associated with stock-car racing in the early 1950s. The film uses Doc's history to explain his bitterness toward the racing world and his reluctance to train McQueen. His experience also gives him the technical knowledge to serve as McQueen's crew chief.
Doc's three championships are an important part of the film's contrast between fame and community. He once sought recognition on the track, but later finds a quieter role helping others in Radiator Springs.