Doc Hudson won three Piston Cup championships in Pixar’s Cars backstory.
The Fabulous Hudson Hornet’s titles came in 1951, 1952, and 1953. Doc’s victories establish him as one of the most accomplished racers in the Cars universe, even though he later leaves professional racing after a serious crash and an unsympathetic recovery period.
By the time Lightning McQueen arrives in Radiator Springs, Doc has become the town’s doctor and sheriff rather than a public racing celebrity. He initially hides his past because he resents how the racing world abandoned him after his accident. His relationship with Lightning gradually reopens that part of his identity.
Lightning’s discovery of Doc’s trophies is a major turning point in the first film. Doc’s three championships should not be confused with Lightning’s eventual Piston Cup result or with real-world Hudson Hornet racing records; the number three is part of the fictional Cars biography.