Other mistake: When Carol leaves her car full of girlfriends to get into John Milner's yellow coupe, she does not reach for his obvious door handle, but instead puts her hand through the open window and uses the inside release. She could not possibly know the outside handle would not work. In another scene, Carol uses the outside door handle.
Other mistake: In the race scene between Milner and Falfa, you can see exhaust smoke coming from Milner's car, but in a previous scene the station attendant mentioned Milner taking the header plugs off. By taking the header plugs off, his exhaust is running from the headers and you wouldn't see exhaust coming from the tail pipes. (01:03:15)
Other mistake: When nerdy guy (glasses) enters the pharmacy and goes to the counter, he nervously requests chewing gum, hair comb, candy bar, pan, batteries, a pint, and beef jerky, which the clerk just turns around and then magically puts into a bag, including the booze, when most of those items, except the booze, should be available on the shelves behind them.