Revealing mistake: When Ali Gator and Windy Winston are coming back from the barfight riding the atv's, Ali scratches his head and you can see where the green glove ends and the actors real skin is supposed to be, under the shirt.
Revealing mistake: When the chipmunks and chippettes and getting ready for the balloon race, Jeanette walks up to Simon and asks him what route to take to Bermuda. Pay attention to Theadore; he's supposed to be in front of Simon handing the chest of dolls to Alvin who is in the hot air balloon. After handing him the chest, he dusts his hands and moves his head a little while doing it. If you look at his head, it seems to cross behind Simon's even though Theadore is supposed to be in front of him. Simon's face may have needed to be seen, but still a mistake.