Continuity mistake: In the opening credits when the title comes up, there is a picture of Mater beside it with the Ghostlight after him. Mater has his right headlight still intact. But during the film, he loses his remaining right headlight moments before he is scared by the lightning bug, before the Ghostlight ever gets to him. (00:00:10 - 00:04:10)
Continuity mistake: When Mater is hiding behind the Roman Coliseum of Tires, Luigi drives up to it as the fork lift finishes the last tire. In the wide shot, Luigi is looking slightly up and has his front end raised just a little. Then it cuts to a close up and Luigi is suddenly looking right at the forklift and has his front end lowered on the suspension. (00:00:30)
Plot hole: Mater tells McQueen he moved and looked like he just saw the Ghostlight. Sheriff gets on to Mater for talking about the Ghostlight and then their whole plan falls into place to trick and scare Mater with the blue lantern. Only there's no way they would have known that Mater would have mentioned the Ghostlight after that. McQueen didn't know about it, supposedly. And he had been scared by Mater and had been there enough that he would have known if Mater had mentioned it before, and Mater would have known he told McQueen. (00:01:55)
Revealing mistake: Right after McQueen asks what the Ghostlight is, it cuts back to the other cars. Luigi is right next to the firetruck and some gas pumps. The firetruck's door is very reflective, and the gas pumps are visible in it. But Luigi is right by the pump, and he is not reflected in the firetruck's door. (00:02:10)
