Cars 3 was the first Pixar Cars film to show Lightning McQueen racing in the Piston Cup after his rookie season.
The original Cars follows McQueen during his rookie campaign, when he competes for the Piston Cup against veteran racers such as The King and Chick Hicks. Cars 2 shifts its main focus to the World Grand Prix and an international espionage plot, so it does not continue McQueen’s domestic Piston Cup season in the same way.
Cars 3 returns to stock-car racing and opens with McQueen established as a veteran champion. A new generation of technologically advanced racers, led by Jackson Storm, begins defeating older competitors. McQueen’s struggle to remain competitive drives the film’s training and mentorship storyline.
The wording matters because Cars 3 is not simply another rookie-season adventure. It presents a later stage of McQueen’s career, including his effort to adapt to changing racing technology and eventually support Cruz Ramirez. Cars Toons is a collection of shorts, not a feature film continuing the Piston Cup storyline.