Continuity mistake: When Toad turns the 58 Impala around to pick up Debbie. She walks past the same Blue Corvair twice. She then steps from the curb to talk to Toad. The Corvair is parked next to the curb. When they switch to the long shot the Corvair has been replaced by a gold coloured Buick. When they drive away the Corvair reappears in its original position.
Continuity mistake: After Carole is hit with the water balloon thrown from a passing car, she tells John Milner to catch them at the light, where he's to flatten their tyres while she sprays the windshield with shaving cream. Carole sprays the front windshield, then starts to go to the back of the car to spray the back window. The front windshield is clean, even though Carole just emptied a can of shaving cream onto it.
Continuity mistake: The girls - whose car tires are about to be flattened and windows about to be sprayed with shaving cream - roll up their passenger window twice during the same brief scene. Once as Milner and Carol are getting out of his hot-rod, and again as John and Carol approach the car.
Continuity mistake: During the first set of cruise scenes, you can see a shot of a yellow '56 Chevy parked on the opposite side of the street with the hood raised and a coupe of guys working on the engine (just after a purple-ish '40 Ford rolls past). In the very next shot, you can see the same car for a very brief moment, this time with the hood down. A few shots later, you see the same yellow '56 yet again, but this time being driven. Finally, in the very next shot, Milner drives past it yet again, still parked on the side of the street, with the hood down.
Continuity mistake: A windshield wiper is visible on Milner's coupe in only three shots. These occur when Carole gets into the coupe from the Studebaker and shortly after, when Milner is pulled over for a defective license plate light. All other shots of the coupe show only the stub of the wiper mechanism.