Continuity mistake: Towards the beginning of the film, as Jeremy Sisto walks down the road, he's wearing a flower necklace in the scene before his girlfriend has picked the flower for him. In the subsequent scene when she picks it, he's not wearing it.
Suggested correction: It's not the same flower, actually. She picked that one when he already had one on his necklace—it's just hidden in this scene.
Plot hole: In the end, the old timer sees the truck approaching and gets up and closes the door and acts as if he's scared. As we learned in part 2, these hillbillies are related to each other. Considering he knows the yellow truck, why does he act afraid? (01:16:15)
Suggested correction: The sequels do not affect the original. Not a valid mistake.