When Officer Moody is sitting in his patrol vehicle getting ready to eat his sandwich, you can see that the unit number of his patrol unit is marked as unit 104. A moment later when he pulls out, the unit is clearly marked 108 in several locations on the car.
When Jo Ann is learning to drive and backing out of her driveway, not only can you see someone's reflection in the back window, but fingers appear on the seat behind her head. Someone is clearly sitting in the car with her even though she is alone in the story line.