Corrected entry: When Justine and her lover leave the motel room and see her husband's van, the front of the van is facing the road. However, when we see the flashback from her husband's friend saying he followed her to the motel, he parks the car facing the room.
Corrected entry: When Justine is in Phil's friend Bubba's house, the Texas flag against the wall is upside down.
Correction: This may be on purpose, to reflect a certain sentiment ...
Correction: When Justine and Holden leave the motel room they do not see her husband's van. She sees her husband's friend's white truck. And as far as I can tell from watching both scenes, the truck is parked facing the same direction both times.