Mutiny on the Buses (1972)

Revealing mistake: When Stan is in the safari park driving the bus with the monkey on the steering wheel the scene outside the bus is obviously background projection and at times it runs backwards giving the impression that the bus is in reverse when all the time it is going forwards.

Revealing mistake: When Stan reverses the bus into Blakey's minivan, crushing it, the van that is crushed is not the same one that is used earlier in the film as it is tatty and has a different grille. Also, the bus parked behind which the van is crushed against is so obviously fitted with an extra panel, to prevent body damage when the van is pushed into it.

Continuity mistake: When the fire starts in the bus depot, the manager tells Stan to reverse the bus away from it, and ends up crushing Blakey's minivan. The van changes from a Morris model to an Austin model, just before it is crushed.