Other mistake: After the first race, in the scene where Lightning is rushing out on the stage thinking he is the winner, loads of confetti is shot out when the King and Chick Hicks gets onto the stage. The confetti is then falling down, but not a single flake hits any of the cars. However, in the following shots, you can see plenty of it on the stage underneath the cars, even though they haven't moved.
Other mistake: During the very last race, Lightning McQueen gets next to Chick Hicks, and the reflection of that his "C" emblem is on Lightning McQueen's hood. However, the C is facing the right way. Since the C is placed on the Chick Hicks in the correct direction, the reflection on Lighting McQueen should be a mirror image.
Other mistake: The monitor from inside Mack's trailer displays his whole face while talking to McQueen. There is no camera outside of Mack that can display him in that fashion.
Suggested correction: The camera in the trailer may be a TV video instead of a camera.
No, McQueen is talking live with Mack through this monitor.
Other mistake: After Lightning is caught in Radiator Springs, he has a boot on his front tire. Mater then tows him to court from the rear, which wouldn't be possible with the boot on.
Other mistake: When Mack wants to pull over because he is getting sleepy a car drives by with a mattress on the roof. There is no reason to have a mattress in a world without people, the cars sleep right on the ground/floor.
