Continuity mistake: Before Lightning falls off the end of Mack's trailer, you can see Snot Rod and one of the other cars running alongside the trailer. But when the camera moves to show Lightning coming off the trailer, you can see alongside the trailer in the background, and the cars are now missing. Camera switches back to the front of Mack, and the cars are back alongside again.
Other mistake: At the start of the film when the commentators are explaining the tie situation between the 3 cars the green arrow to the car is out of alignment and misses the car, instead pointing at the track.
Trivia: The canyon around Radiator Springs looks like old car bonnets and ornaments.