The markings on Mallory's house are a reference to Hurricane Katrina, as rescue workers and the Army National Guard would spray paint an X on each house or building that had been cleared.
Director Jake Scott and costume designer Kim Bowen accompanied Kristen Stewart to strip clubs to research her role as Mallory. During that time Stewart was offered jobs by club owners because they didn't know she was an actress.
When Allison is in the car counting her money she burns her fingers on the butt of her cigarette. In the following scene she is seen with a barely smoked cigarette.