If Trudie wanted to get rid of her curls, all she had to do was wash her hair. Perms can't be washed for 2 days otherwise the curls don't keep.
The movie is set in a wintry climate, but the store where they stop to buy gas only has a screen door on the front.
The police tell Raj that David's kidnapping was "apparently at gunpoint." But David never told Jessica about the gun when he called her for help.