Revealing mistake: When Dewey is singing the protest song about midgets in 1966, modern cars can be seen driving in the background.
Revealing mistake: In the jazz club, the saxophone player's finger movements don't match what he is playing.
Revealing mistake: When the chipmunks are singing 'How we roll' there is a shot of Ian with some people in a private room. The music continues to play as they listen and the stage is reflected in the glass, how ever the chipmunks, back up singers, dancers, instrument players and audience are missing. (01:17:40)