Writer Stel Pavlou was working as an assistant in a liquor store when he penned his screenplay. It was sent on spec to Tim Roth as Pavlou knew that Roth insisted on reading all independent scripts sent his way.
During the car chase, McElroy and DeSuza are trapped in an alley by an unmarked police car. The police car pulls up along side a parked car, but in a subsequent camera shot, the parked car is gone.
When Elmo and Felix are driving around Liverpool, they go from Liverpool town center to Old Swan (about 4 miles away), then back to the town center in a matter of seconds.