The original Cars took place almost entirely in the town of Radiator Springs, and as such the characters who lived there were vital to the story.
The tow truck took a major role while other characters still had a significant part.
I had the opportunity to see a large piece of Cars 3 and, with the exception of one early scene in the film, the town of Radiator Springs and the people who live there were nowhere to be seen.
While the sequel didn’t spend much time in the town, several of the townsfolk traveled with Lightning as part of his pit crew, and ultimately Cars 2 was a movie about Mater, not Lightning.