A couple of goofs? (spoilers, of course)
1. There's a small drop of blood on the wall of the house the PI's break into. The dude shot himself in the face, where's the rest of the blood, bone, and tissue that should be all over the floor and wall?!
2. When the little kids bust into the room while the teens are going at it, they hear the blaring horn for the first time, yet no one notices/says anything about it? WTF?!