A Scooby-Doo Valentine - S3-E3
Plot hole: It's never explained how JC Chasez and the Hollywood extras impersonating the gang gained the super strength they possessed to do things like ripping car roofs open or holding up the Mystery Machine.

Starring: Frank Welker, Grey DeLisle, Mindy Cohn, Casey Kasem
A Scooby-Doo Valentine - S3-E3
Plot hole: It's never explained how JC Chasez and the Hollywood extras impersonating the gang gained the super strength they possessed to do things like ripping car roofs open or holding up the Mystery Machine.

Continuity mistake: In the opening title sequence, when the mummy appears behind the gang, you can see his red eyes. But in the next shot, his eyes are missing. (00:00:45)
Answer: Because of the goo that was on it.