Doc Hudson had won three Piston Cup championships before Pixar’s Cars begins.
The film reveals Doc’s racing history as part of the story of Radiator Springs. He was a celebrated racer known as the Fabulous Hudson Hornet, but a serious crash ended his career and left him disillusioned with the racing world.
Doc’s three championships are important because they explain why he recognizes Lightning McQueen’s talent and also why he initially resists helping the young newcomer. Lightning’s arrogance reminds Doc of the way racing fame can isolate a driver.
The Piston Cup is fictional, although its presentation draws on American stock-car racing and NASCAR traditions. Doc’s character is based on the real Hudson Hornet, a car associated with early-1950s racing success, but Doc himself is an invented character.