Audio problem: When Thelma approaches the Highway Patrolman's window you can hear her cocking the revolver she then points at his head, but the revolver remains visibly uncocked.
Audio problem: Right after the girls blow up the tanker, there is a sequence with scanner traffic. They show some helicopters. Right at the beginning of the scene with the choppers, the audio of them cuts out for a split second.
Answer: It's the 1941 film "Penny Serenade".
Sierra1 ★