The bad men are tying up Ernie in his wheelchair. Between shots the ropes wound around him completely change position.
Palmer and Pearl are driving a truck that has been locked in California by Ernie. Ernie told them that his brother in Florida has the key. While still on the road, Pearl opens the back of the truck without any problem or any key.
The bad guy is being electrocuted in the trailer by the Christmas tree. Check out his legs when he's "on fire". Someone simply overlaid a "fire effect" over his picture. His legs flail, but the fire's base doesn't move.
Palmer blows a tire on his rig. When they pull over, stop, and get out, the camera crew is reflected in their bumper.