In an aircraft hangar, against a gleaming plane, Catherine Ballard is seen having sex with a swarthy guy who takes her from behind. At the same time in a film set camera room, producer James Ballard is having sex with a camera girl over a table. Later that evening in the Ballards' high-rise apartment, they calmly discuss the respective trysts as part of their open marriage. When he tells her that he didn't come, she distantly replies, "Poor darling. Maybe next one, maybe next one...." Ballard takes Catherine and has rough sex with her from behind as she leans over the balcony of their apartment, set against the tiny Toronto freeway traffic below.
Another evening later, as Ballard drives and riffles through papers, he loses control of his car, which jumps carriageways and smashes into another car head-on. The driver of the other car is killed as he plunges through his car's windshield and through Ballard's windshield; his hand bears the imprint of the bonnet insignia. The female passenger of the car fumbles with her seat belt, exposing her left breast. She and Ballard stare at each other in shock.
Ballard is seen shuffling along a hospital corridor, his broken leg encased in steel pins and scaffolding. The female passenger, Dr. Helen Remington, gives him a withering look as she walks stiffly by with her own injuries. A man in white overalls, holding photographs of auto crash wounds, examines Ballard's injuries with great interest. In the isolated ward, Ballard and Catherine indulge in a spot of mutual masturbation as she describes the shattered wreck of his car.
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 against a plane. After going home, Ballard then has sex with Catherine, which is getting more urgent as he takes her from behind again.
Another few nights later, Helen meets with Ballard again where she takes him to an event staged by the enigmatic Vaughan: a reconstruction of James Dean's fatal 1955 crash in his racing Porsche, Little Bastard. Ballard recognizes Vaughan as the man from the hospital several weeks ago. The accident is restaged without safety gear for Vaughan or his two stunt drivers, Seagrave and Trask. Watched by a small crowd, the two cars impact head on at speed. Trask is okay. Vaughan struggles painfully from the wrecked Porsche, but Seagrave, who was driving him, is only semi-conscious. Over the PA speakers, Vaughan announces, "James Dean died of a broken neck and became immortal." Just then, police sirens are heard as the crowd scatters in all directions. Ballard and Helen run with Vaughan through the nearby woods, where they reach Vaughan's battered black Lincoln convertible. As he drives away from the scene, Vaughan fingers Helen while Ballard watches with curiosity.
A short time later, Vaughan, Helen, and Ballard arrive at an unkempt communal house. Vera Seagrave attends to her husband's injuries while callipered crash victim Gabrielle offers everyone joints to smoke. Everyone is soon wasted on the pot. Vaughan talks to the concussed Seagrave about recreating Jane Mansfield's fatal crash. Producing an album of crashed photographs, he describes his project about re-enacting fatal auto crashes as the reshaping of the human body by modern technology.
Another day later, Ballard and Catherine drive in separate cars. At an intersection, Vaughan draws up behind Catherine's silver sports car and follows aggressively before she pulls off the road. When Ballard takes her from the rear once more, she incorporates Vaughan into the act, asking if Ballard would like to sodomize him in his big car. Ballard backs away with slight disgust.
At the airport garage, Ballard and Helen meet where they again have sex. Discussing her sexual exploits in cars, Helen admits to a fantasy of Vaughan photographing them as if they were in traffic accidents. Later, back at the commune house, Vaughan and his group smoke more joints and watch crash-test videos. They are all sexually turned on by the violence of the crashes on the screen.
Driving around airport perimeter roads, Ballard connects Vaughan's Lincoln convertible with the 1963 JFK assassination. Vaughan tells him, "The car crash is a fertilizing rather than a destructive event--a liberation of sexual energy of those who have died, with an intensity that is impossible in any other form." It is clear that this Vaughan's real desire: the ultimate existential experience. He picks up an airport hooker and has sex with her in the back seat while Ballard drives and watches in the mirror.
As Catherine and Ballard leave the studio for the day as he tells her more about Vaughan's underground sub-culture of crash victims, Vaughan arrives to pick them up when he is questioned by the police about the death of a pedestrian near the airport. He is shaken as Ballard drives his car.
On the local freeway, Vaughan, Ballard, and Catherine encounter a multi-vehicle accident. Vaughan takes crash photographs, then stages more using Catherine as a model. The EMTs working on the wrecks are too busy to care. In the front wreck, Vaughan finds the dead Seagrave, dressed as Jayne Mansfield, complete with a scalped blond wig and a dead dog in the back seat. Vaughan is amazed that Seagrave went through and reenacted the fatal crash on his own.
After Ballard finds blood on Vaughan's car, they go to a car wash. In the back seat, Vaughan has brutal sex with Catherine in the back seat under the gaze of an entranced Ballard, who later examines his bruises and scars on his healed leg in silence.
In an auto showroom at a local car dealership, Gabrielle is helped into a Mercedes by an embarrassed salesman as Ballard looks on, amused by Gabrielle fondling the car, and saying how it turns her on. A little later at the airport garage, Ballard arranges Gabrielle's broken and scared body in order to access a healed crash-wound in her rear thigh.
Vaughan phones Ballard to meet with him to witness his prophetic medical tattoo: a steering-column indentation on his torso. He encourages Ballard to have a small insignia on his thigh. Later, in a junkyard, Ballard and Vaughan finally have gay sex in the back seat of the Lincoln. Afterward, as Ballard sits behind the wheel of a wrecked car, Vaughan slams into it. The next day, Catherine's silver sports car has also been rammed.
As Ballard drives around the airport perimeter, Vaughan's car launches out of nowhere; he is in a delirium as he toys with Ballard's sports car, ramming into it playfully before he accidentally swerves over a parapet and landing on a coach below. Ballard stops and surveys the carnage as Vaughan lies dead among the wreck.
The next morning in the impound lot, Gabrielle and Helen arrive to look at Vaughan's wrecked Lincoln, where they begin making out with each other and they have lesbian sex in the back seat of the late Vaughan's car.
Ballard decides to go to the pound to reclaim Vaughan's car. On the open road, he drives the Lincoln as recklessly as Vaughan, overtaking several vehicles in pursuit of Catherine whom is driving her car on the road ahead. He rams into her car, running it off the road and down an embankment. Ballard stumbles out of the Lincoln and painfully stumbles down the embankment. Catherine is lying on the ground, having been thrown from her car, alive but seriously wounded, with her skirt around her waist. Ballard lies down next to her, caresses her bloodied body, and when she says she's all right, he takes her from behind again, having sex with her on the grass embankment. He tells the semi-conscious Catherine as he climaxes: "Maybe the next one...."