Factual error: When the cop car loses its axle, the movie playing at the theater is Dementia 13, which was released in 1963, while the movie was set in 1962.
Factual error: In the beginning of the movie, set in the early 60s, Laurie drives her Edsel into Mel's. As she is waving to Steve, you can see a Brown 70s AMC Gremlin, a red 70s Ford Maverick, and a two-tone late 60s Chevrolet van parked on the street in the background.
Factual error: When Laurie arrives at Mel's parked behind the already said red mustang there's a brown car which looks like an AMC Gremlin, only introduced in 1970.
Continuity mistake: Curt waits in his Citroen for a phone call from the Blonde in the T-Bird. He is sleeping and the camera shot shows him about 15 feet away from the phone booth. The phone ringing awakens him. The following shot shows him coming to and dashing for the phone. After exiting the car, he takes about two steps, and he's already in the phone booth. Either the car had magically been moved up closer to the phone booth for that shot, or he averages about 7 to 8 feet per step to reach the phone in time.