Continuity mistake: The vehicle used by the person delivering newspapers (an Austin Mini I believe) has, in one scene, an "A" license plate and in the other scenes it has a "B" plate.
Continuity mistake: In the scene near the end, when the band finds out that Jim has been taping their songs, Dave is wearing black nail-polish. Then when he threatens to 'pull out his can of Whoopass,' it's not there.