In the opening credits, Louise Currie is listed as "Sally". Yet, within the film, she's called "Stella Saunders".
Constant mix of daytime and nighttime shots, when the scene supposedly takes place at night.
A Kidnapped Girl (Terry Walker) pulls her car into the gas station to ask for directions, you can see that the windshield wiper is on top and has a "B" sticker in the front windshield but moments later when she is apprehended she is in a different car. That car is a darker color, has two windshield wipers on bottom, and an "A" sticker in the front windshield.
In the scene toward the end in which Ralph finds his abandoned car in the woods and calls for Betty, the movements of crew members are reflected in the car's rear view mirror.