Lead actor Stephen Dorff is really claustrophobic. Director Gabe Torres did not know this until after filming wrapped. Torres stated that Dorff's willingness to stay inside a glass box for the duration of filming was "extreme method acting".
The phone numbers that are used in this movie are not the traditional 555 numbers used by Hollywood. Actually, the number that Henry gives as his home number is for the Norfolk Baseball Academy in Virginia.
Director Gabe Torres wanted to do a Die Hard-style thriller that took place in a single location. He contacted his agent and she started looking at scripts. She called him and asked him if he wanted to consider a movie that took place in the trunk of a car. He asked "how much?". She responded "all of it".
Composer Brian Tyler's soundtrack involved actual car part noises. Tyler claims that many filmmakers have since come to him and asked him to do another score similar to Brake's, even though many laughed at the idea of an experimental score utilizing car parts.
Roulette is a form of gambling where players choose to place bets on either a single number or a range of numbers, the colors red or black, or whether the number is odd or even. The bunker in the film is also code-named "Roulette" because it changes without notice and only a few people know where it is on a given day. The bunker in the film being called "Roulette" not only references the casino game and how it resembles the way the bunker operates, but also is a reference to Jeremy's gambling addiction.
Jeremy Reins mentions that he is in a trunk of a car, likely a long car with a large-cylinder engine due to the large size of the trunk. He wasn't wrong; the car used by the filmmakers was a 1998-2002 second generation series Ford Crown Victoria (or "Crown Vic") four-door sedan with a 4.6 Liter SOHC Modular V8 engine. The car was so chosen for its large and spacious trunk, and because the Ford Crown Victoria Police Interceptor was also a standard vehicle used by the United States Capitol Police at the time, since the terrorists were pretending to use a police car. This is further evidenced when Jeremy escapes the trunk at the end of the film, the car is a Crown Victoria.