Revealing mistake: During the chase sequence towards the end of the film, Roger shoots five bullets into the windscreen of the blue car. If you look carefully, you can see there is no driver in the front seat.
Revealing mistake: When Frank kills one of the rattlesnakes with a ski-pole in the RV, you can see that he is just stabbing the floor and not the snake.
Revealing mistake: During the chase sequence towards the end of the movie, Roger throws fire bombs using to eliminate one of the cars that are pursuing the RV. If you look carefully, the car starts to flip before the explosion.
Revealing mistake: Just over an hour into the film, Frank says to Roger that the oil cooler is "mashed up against the radiator there". But there is no damage to the grill.
Revealing mistake: During the car chase towards the end of the film, the man who is trying to put gasoline in the RV gets killed when he is hit by the by-pass. The 'dead' man falling off the RV is a dummy as its legs and arms look unnatural.