Factual error: At the start of the movie, the nuclear-powered articulated bus that is attempting a non-stop land run to Denver leaves New York City, but you can see the Rocky Mountains in the background.
Continuity mistake: When the bus is brought out of the hangar for its maiden trip, the top of the front of the bus just clears the top of the roof. When it parks outside, the rear section has a glass roof which wouldn't clear the roof without damaging either the bus or the hangar roof.
Audio problem: When Mr Ames says "Jack quit" to Scotty, his mouth doesn't move.
Audio problem: When the lifeguard says "Come on, everybody" at the swimming pool, his mouth doesn't move.