In Pixar's Cars 3, Doc Hudson inspires Lightning McQueen's training plan.
After a crash against the younger Jackson Storm, Lightning remembers Doc's advice and racing history. Doc was the Hudson Hornet who won three Piston Cups and later became Lightning's mentor in Radiator Springs.
Lightning studies Doc's old racing methods and visits places associated with his past. The training journey leads him to Smokey, Doc's former crew chief, who explains that Doc did not simply disappear after losing his competitive edge; he found purpose by helping Lightning.
This connection makes Doc central to Cars 3 even though the character does not receive new spoken dialogue. Paul Newman, who voiced Doc in Cars, died in 2008, and archival material was used for the character in the third film.