Judy & I went to see "Cars" yesterday - fun movie, and great animation but that's what Pixar does.
I'm sure a lot of liberties were taken, but it's obvious that someone on the production team knew something about cars and racing, NASCAR in particular. Those of us who remember Richard Petty's mid-air pirouette will recognize it near the end of the movie.
I really began to appreciate their efforts when one of the primary car-acters, a Hudson Hornet, fired up about half-way through the movie: it actually sounded like a six, a reasonably hot one. That required some thoughtful attention to detail on someone's part.