Revealing mistake: In the scene when Christine smashed repeatedly into the silver Camaro at the gas station, there is no motor in the Camaro. The hood of the Camaro gets knocked off the hinges and is twisted sideways on the car. As Christine is in reverse and dragging the Camaro along you can see down through the hood that the engine compartment is empty. Minus a transmission also, I believe.
Continuity mistake: At the the end of the film, Dennis uses the Caterpillar tractor to ram Christine. He also immobilizes the car by dropping the teeth of the loading bucket into the roof. Then we see close-ups of the car repairing itself completely. The next shot, just before the tractor starts to crush the car, shows the car in its previous smashed-up condition again.
Trivia: When Arnie and Leigh discover that the car has been trashed at Darnell's Garage and Arnie suddenly turns on Leigh, yelling at her and shoving her backwards, note the look of shock on her face - it's real. Keith Gordon (Arnie) explains on the DVD that in rehearsing the scene, he purposely didn't react as violently, so when the scene was shot, his behavior change actually shocked Alexandra Paul (Leigh).