Paul Thomas Backes

Continuity mistake: In the scene where Mater and Lightning enter Buckingham Palace, you can see a mountain as you look in the background. But when Finn and Holley enter while Lightning and Mater are moving closer to the Queen, the mountain has now become a tall building.

Paul Thomas Backes

Continuity mistake: Tony Trihull appears when Finn McMissile begins chasing Professor Z. It also shows when Tony uses his magnet. When it is used, Finn's equipment are pulled by the magnet, which includes his bullets. Those bullets are black when all of them were going out. However, when they are pulled onto the magnet they are grey.

Paul Thomas Backes

Other mistake: In London, the red telephone boxes seen are human-sized, so it is impossible for them to be big enough for the cars to even get into.

Paul Thomas Backes