Cars was Pixar's first feature film centered on anthropomorphic vehicles. Released in 2006, it introduced Lightning McQueen, Mater, Sally Carrera, Doc Hudson, and the other residents of Radiator Springs.
The film follows Lightning, a rookie race car who becomes stranded in the forgotten Route 66 town while traveling to the Piston Cup finale. His forced stay changes his priorities and introduces the audience to a community whose identity is tied to the old road. The story combines sports competition, road-movie elements, comedy, and a small-town character drama.
Cars was followed by Cars 2 in 2011 and Cars 3 in 2017. Planes, released in 2013, was produced by Disneytoon Studios rather than Pixar, so it is not the answer to a question about Pixar's first vehicle-centered feature. The original Cars is also distinct from Pixar's earlier films, whose protagonists include toys, insects, monsters, fish, superheroes, and robots.