Beth's nail polish changes from one scene to the next during the course of a single day. In some scenes, she's wearing dark nail polish. In other scenes, it's a clear or very light nail polish or none at all.
The "ice cubes" that Beth pours in the motel bathtub to help Mick with his hunger are visibly and opaquely plastic and fake. Real ice cubes would be clear.
Mick has a pierced left earlobe. A man in the 1950's would not have a pierced ear and if Mick has his ear pierced as a Vamp it would heal.