Continuity mistake: When Max is running out of the school after successfully becoming cool. We see his friend with the orange mohawk at least twice. Once hanging from a statue, and another where he's reaching out from a school bus. These two shots are really close together so there is no way that he could have moved that quick.
Continuity mistake: In the scene at the diner, we see Max's breakfast of bacon and eggs. In the following shot he's in, the bacon disappears, only to reappear in the next shot of him.
Max: Why are you doing this to me, Dad?
Goofy: 'Cause, I don't want you to end up in the electric chair.
Max: Dad... listen, about my directions... will you listen to me? I gotta tell you something, Dad.
Goofy: Why bother? I'm probably too stupid to understand anyway, right?
Max: Forget it.