Revealing mistake: As Lex is walking away from the container that holds Superman's body, the glass of the container is reflected in the floor, as is Superman's body. But the little pedestal that he is hovering above is not reflected. (00:43:30)
Revealing mistake: The opening shot of the movie shows a rabbit hopping up from the bank of a road and then being hit by a car. You can, however, tell that the rabbit is not real because as it moves up the bank, none of the grass moves as the rabbit bounces through it. (00:01:05)
Revealing mistake: Right at the start, when all the police cars skid to a halt, there are tyre marks on the ground from previous takes. (00:00:30)
Revealing mistake: The '70 Challenger doesn't have a framed door - thus no place to anchor the belts.
Suggested correction: They're anchored to the floor.
Revealing mistake: After "Do you want to die with dignity" all hitmen drop their magazines of blanks.
Revealing mistake: Meatwad and Shake get booted off the computer by Frylock so he can find instructions to the Insane-O-Flex. Watch the computer monitor. It rumbles, but the logo on it stays still.