Doc Hudson was the famous Piston Cup racer known as the Hudson Hornet in Pixar's Cars.
Doc is introduced as the respected physician and judge of Radiator Springs, but the film later reveals that he was once a champion racer. He won three Piston Cups and became known as the Fabulous Hudson Hornet before a crash ended his racing career. His experience helps him recognize both McQueen's talent and the dangers of arrogance.
The character is voiced by Paul Newman, whose own public image as a racing enthusiast added special significance to the role. Newman had competed in motorsport, including professional sports-car racing, before joining the voice cast.
Doc's story is partly inspired by the real Hudson Hornet, a car associated with stock-car racing success in the early 1950s. The animated character's career belongs to the film's fictional history, however, and is separate from the real automobile's racing record.