In the UK the Daily Mail newspaper led the calls for the film to be banned with a front page headline reading "Ban This Car Crash Sex Film". To cover themselves against possible prosecution the BBFC consulted a QC to determine whether the film contravened the Obscene Publications Act, a psychologist to see if it could potentially incite copycat behavior, and a group of disabled people to see if the character played by Rosanna Arquette would be considered offensive to them. After all 3 consultations proved to be successful and the BBFC were able to pass the full unrated version completely uncut.
Sex scenes between Ballard and his secretary were filmed but cut because director David Cronenberg felt the actors' chemistry was too good, contravening the nature of all the other relationships in the film.
In the novel by J.G. Ballard from which this film derives, Vaughan's goal is to achieve sexual climax by crashing his car into the limo of Elizabeth Taylor, and gruesomely killing her, a plot item not retained (obviously) for the film.
Vaughan's "benevolent psychopathology" speech ("The car crash is a fertilizing, rather than a destructive event . . . ") is taken word-for-word from a passage in J.G. Ballard's 1970 book "The Atrocity Exhibition", published three years before the novel "Crash".
Because Vaughan's car becomes increasingly battered over the course of the film, the production required six vintage Lincolns: three for driving, one for smashing, one cut in half for studio shots and one converted into a pickup truck on which to rear mount the camera to capture driver and passenger POV's.
In the UK this film is banned from sale or theatrical exhibition within the city of Westminster (London), although it is possible buy the DVD in greater London and (in theory) see the film at a cinema outside of Westminster (this was true at the time of cinematic release). Also, similar theatrical bans were placed in other parts of the UK cities (including Chester, Cardiff and Durham to name a few...)