Revealing mistake: When the trucks start circling the Dixie Boy the red garbage truck hits a telephone booth. A human arm is visible, you can also see an arm in the orange Bic truck when it cuts into the blue 15 truck.
Revealing mistake: After Hendershot blows up the two trucks, Brett runs into the door. It's very obvious the glass was removed and replaced with plastic because it makes a plastic sounding noise and wobbles.
Revealing mistake: When the red Autocar garbage truck hits the bible salesman's car, you can see a harness holding the two front tires in place for the truck to make the car fishtail.
Revealing mistake: When Hendershott is shot after shooting the bulldozer, you can see the blood packs used under his shirt.
Revealing mistake: When the lawn mower starts itself and tries to pursue Deke, from the back, the front wheels are on the ground and rolling. From the front angle, the front wheels are off the ground. There is a piece of material on the front that was added to hide the steering rig used to make it turn to chase Deke, but the rig's wheels are just visible.
Continuity mistake: The angle and height of the bridge changes depending on close ups and long shots.
Visible crew/equipment: During the ballpark scene, when the cans strike the coach they show a shot of the kids and there's a person in the background with a blue shirt standing there, then the cans attack the kids and he's walking around like nothing's happening. Obviously he's not supposed to be in the movie.
Continuity mistake: When Curtis is looking inside the gas station, if you look to the left where the pile of junk is, there's a white vehicle that's missing both headlights. After the tow truck tries to hit Curtis the white vehicle in the junk pile has a brand new left headlight.
Audio problem: In the end when Brad is taking the dead woman's ring, the Happy Toyz truck is sitting there silently. If you look closely, you can see a gentle stream of exhaust from the pipes, meaning that the truck is idling. Yet a moment later you hear it starting up.
Factual error: A big sign at the pumps states that diesel is priced at $1.089, yet when the trucks are being filled, the price per gallon is around 55 cents. In the 70's, when product reached the $1 mark, pumps were set to half price, and the customer paid double the total, but by 1987, the time frame of the movie, the pump computers would have been replaced to show true pricing.
Factual error: When the fuel tanker comes over to have Billy drop fuel, he pulls the hose down and plugs it into the tank receptacle. The troubles here are that 1) the hose wouldn't be connected in transit, it would be stowed on the side unconnected. 2) elastic straps are usually employed to keep the hoses secured until the tanker gets to its destination to drop the load.
Other mistake: When the Happy Toyz truck is first being fueled, the nozzle handle is locked into the fuel position. When you hear the click of the nozzle stopping, the handle doesn't disengage as it should. When the attendant checks it, he unlocks the handle, and doesn't squeeze it again. Even accounting for the comet's effects, the handle must be squeezed to splash fuel in the man's face.
Continuity mistake: When the newlyweds wait for the gap in the line of trucks, their car has a mattress on top, covering the car. But seconds later, it is gone and never reappears.
Continuity mistake: After Deke unloads into the burger joint's sign to silence the speaker, and in revenge for his dad, after all the commotion is done two holes magically appear in the front cover.
Factual error: When they run out of fuel at the pumps, a truck with placard 1203 rolls up for Emilio to refuel the underground diesel tanks. Diesel is 1202 - 1203 is gasoline.
Revealing mistake: When the trucks start circling the Dixie Boy the blue truck turns in front of the orange Bic truck if you look real close you can see a hand on the steering wheel turning the blue truck. (00:15:00)
Revealing mistake: When Curtis and Connie attempt to get into the Dixie Boy their stunt doubles are visible.
Visible crew/equipment: As Bill and the rest go back inside after the two trucks get blown up, the camera and cameraman are reflected in the door.
Visible crew/equipment: As the girl sneaks up on Bill as he's checking out the Happy Toyz truck, the lighting rig and equipment is reflected on the left brake light lens.
Answer: The Pinball Machine overloaded at speed.