Smokey trains Lightning McQueen in Thomasville in Pixar's Cars 3.
Smokey is a retired racing champion who knew Doc Hudson and helps Lightning rebuild his confidence after his damaging defeat by Jackson Storm. He teaches Lightning to rely on experience, adaptability, and a better understanding of the track rather than simply trying to match newer cars' raw speed.
The Thomasville section introduces several veteran racers and connects Lightning's present to Doc Hudson's past. Smokey preserves stories about Doc and explains that Doc had stopped racing because he was pushed aside by a newer generation of competitors.
Doc Hudson is Lightning's former crew chief and mentor in the first Cars, but he is not the trainer in Cars 3 because the character died before the film's events. Sarge is a military surplus vehicle in Radiator Springs, and Tex Dinoco is a business owner and team sponsor.