Revealing mistake: When Scotty tells Dan to test the bus' aerodynamics, the bus passes the same scenery multiple times.
The Big Bus (1976)
1 revealing mistake - chronological order
Directed by: James Frawley
Starring: Stockard Channing, Rene Auberjonois, John Beck, Joseph Bologna
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.
Dan: Quick, how many decisions have I made today?
Trivia: At the Iron Man's house, there is a painting of the Hindenburg airship disaster. Rene Auberjonois (Father Kudos) had previously starred in the 1975 movie The Hindenburg as Major Napier.