Visible crew/equipment: In the scene where Luke has stolen the Jaguar from the old rich guy, there is a part where Luke drives the Jag up the wall of the tunnel and lands it on top of a truck. It is obvious that the car that goes up the wall isn't even real, it looks more like a Matchbox or Hotwheels car....
Other mistake: In the scene where the one guy is dragging the dead guy around on the creeper and is about to cut the old man's hand off you can see the old man blink and move his eyes. He's supposed to be dead. If he was alive I'm sure he'd have made some noise when he got his hand cut off.