Set in Toronto, James Ballard (James Spader), a film producer, has an open marriage with his wife, Catherine (Deborah Kara Unger). The couple are shown early on in the film engaging in various infidelities. Catherine is aroused by the touch of her breast on bare metal, as she is taken from behind. James is shown to be having sex with a camera girl, inside the camera room, on the sets of his movie.Later having unenthusiastic sex; their arousal is heightened by discussing the intimate details of their extramarital sexual encounters.While driving home from work late one night, Ballard's car collides head-on with another, killing the male passenger. While trapped in the fused wreckage, the driver, Dr. Helen Remington (Holly Hunter), wife of the killed passenger, exposes a breast to Ballard when she pulls off the shoulder harness of her seat belt.While recovering, Ballard meets Dr. Remington again, as well as a man named Vaughan (Elias Koteas), who takes a keen interest in the brace holding Ballard's shattered leg together and photographs it.Ballard is kept in an isolated ward meant for air crash victims, where Catherine visits him and they both masturbate each other, while Catherine narrates the crash.After going home, he scans traffic through his binoculars. Ballard says that there seems to be more traffic since the accident. Getting behind the wheel again of a rental car, Ballard drives to examine his car at a local impound lot. Helen Remington is also there.Ballard drives her to the airport, where she tells him her name and that she works in immigration. They almost get into another car accident when a car cuts in front of them. She suggests going to the airport garage, where they have frantic sex inside Ballard's car. After going home, Ballard then has sex with Catherine, which is getting more urgent as he takes her head on.In an attempt to make some sense of why they are so aroused by their car wreck, they go to see one of Vaughan's cult meetings/performance pieces, an actual recreation of the car crash that killed James Dean in 1955 with authentic cars and stunt driver Colin Seagrave (Peter MacNeill). Vaughan was earlier a specialist in International computerized traffic systems.When Transport Ministry officials break up the event Ballard flees with Seagrave, Remington and Vaughan. Vaughan touches Remington as he drives them to his hideout.While flipping through the photo diary, Ballard sees crash photos of Gabrielle, and also of Ballard and Remington having sex.Later, Ballard is following Catherine, while she is driving her car. He notices Vaughan pulling up behind Catherine and driving really aggressively, almost hitting Catherine's car multiple times. Vaughan only backs off when he sees Ballard stepping in. That night Ballard takes Catherine again from behind. Catherine asks Ballard if he would sodomize Vaughan in his big car. Ballard finishes aggressively with Catherine.Later, Ballard has sex with Remington in the airport parking garage.Ballard becomes one of Vaughan's followers who Fetishize car accidents, obsessively watching car safety test videos and photographing traffic accident sites. Ballard drives Vaughan's Lincoln convertible around the city while Vaughan picks up and uses street prostitutes. Catherine comes by to pick up Ballard, but the 3 of them end up going on a drive together and pass by a highway accident. While Vaughan gets down to take some pictures, Catherine also is aroused by the accident and gets down from the car to live the experience. Vaughan is horrified to find that one of the dead bodies is that of Seagrave, who went ahead and recreated their next crash project all by himself.Ballard takes the Lincoln convertible through a car wash and watches as Catherine and Vaughan have sex in the back of Vaughan's car.In turn, Ballard has a dalliance with one of the other group members, Gabrielle (Rosanna Arquette), a beautiful woman whose legs are clad in restrictive steel braces, and who has a vulva-like scar on the back of one of her thighs, which is used as a substitute for a vagina by Ballard. The sexual couplings in (or involving) cars are not restricted to heterosexual experiences.While watching videos of car crashes, Dr. Remington becomes extremely aroused and gropes the crotches of both Ballard and Gabrielle, suggesting an imminent three-some.Vaughan and Ballard eventually turn towards each other and have a homosexual encounter. Later on, Gabrielle and Dr. Remington begin having a lesbian affair.Though Vaughan claims at first that he is interested in the "reshaping of the human body by modern technology," in fact his project is to live out the philosophy that the car crash is a "fertilizing rather than a destructive event, mediating the sexuality of those who have died with an intensity that's impossible in any other form."Vaughan and James go for a drive in separate cars, aggressively pursuing each other. On an overpass, Vaughan intentionally crashes his car, landing on a passenger bus below, killing himself. After Vaughan's death, Gabrielle and Helen visit a junkyard, and affectionately embrace while lying in the wreck of Vaughan's car.Later, James and Catherine perform a similar stunt, with James pursuing her on a freeway at a high speed. Catherine unbuckles her seat-belt as she sees James approaching, and he rams into the back of her car, forcing it to topple down into a grass median.James exits his car and approaches Catherine's, which has flipped upside down. Catherine lies partly under the car, apparently superficially injured. When James asks if she is okay, she tells him she is not hurt. As the couple kiss and begin to have sex near the wrecked vehicle, James whispers to her, "maybe the next one", implying that the only possible apotheosis of their extreme fetish is death.