Doc Hudson won three Piston Cups before becoming Radiator Springs’ doctor.
Doc’s former racing identity is the Fabulous Hudson Hornet, a famous competitor from an earlier era of stock-car racing. The film establishes that he won the Piston Cup three times, making him one of the most accomplished racers in the Cars universe.
His career ended after a serious crash and an unsympathetic return to competition. Although he recovered physically, the racing world had moved on and treated him as obsolete. Doc then withdrew from racing and built a quieter life in Radiator Springs, where he served as the town’s doctor and judge.
Lightning McQueen initially fails to appreciate Doc’s achievements. Once McQueen learns the truth, he begins to understand that experience and character matter as much as speed. Doc’s history also explains why he recognizes the dangers of fame and why he becomes an important mentor to McQueen.