Doc Hudson won three Piston Cups before retiring from racing in Pixar's Cars.
The film reveals Doc's history when Lightning McQueen finds newspaper clippings identifying him as the Hudson Hornet. Those reports establish that he was a celebrated champion rather than merely an old car living in a quiet town.
Doc won three Piston Cups in a row, but a serious crash ended his racing career. After recovering, he discovered that the racing world had quickly replaced him with newer stars. This experience explains his bitterness toward McQueen's early arrogance and his reluctance to discuss his past.
Doc's history also draws on the real Hudson Hornet, a car that achieved major success in early NASCAR competition. The fictional championship record is specific to the Cars universe, while the Hudson Hornet name refers to a real automobile produced by the Hudson Motor Car Company.