Factual error: A map of Canada appears behind the guys as they're being questioned by the Mounties. The territory of Nunavut, which was not officially drawn until the year 2000, appears on the map. It definitely did not exist in 1978. (00:18:45)
Factual error: The city of Winnipeg is spelled incorrectly on a road sign that appears while they are at the border, spelled 'Winnepeg'. (00:09:35 - 00:10:10)
Continuity mistake: Aston Kutcher slides out behind the car and screams in excitement while blowing an air horn. When he does, the wind messes up the front of his hair. A few shots later, it's neatly combed again.
Chosen answer: Danny Masterson is the one who screams "hello Wisconsin".