Were there any limits to Vaughan's irony? When I returned from the bar he was leaning against the window-sill of the Lincoln, rolling the last of four cigarettes with the hash kit kept in a tobacco bag in the dashboard locker. Two sharp-faced airport whores, barely older than schoolchildren, were arguing with him through the window.

'Where the hell do you think you were going?' Vaughan took from me the two wine bottles I had bought. He rolled the cigarettes on to the instrument binnacle, then resumed his discussion with the young women. They were arguing in an abstract way about time and price. Trying to ignore their voices, and the massed traffic moving below the supermarket, I watched the aircraft taking off from London Airport across the western perimeter fence, constellations of green and red lights that seemed to be shifting about large pieces of the sky.

The two women peered into the car, sizing me up in a one-second glance. The taller of the two, whom Vaughan had already assigned to me, was a passive blonde with unintelligent eyes focused three inches above my head. She pointed to me with her plastic handbag.

'Can he drive?'

'Of course – a few drinks always make a car go better.'

Vaughan twirled the wine bottles like dumb-bells, herding the women into the car. As the second girl, with short black hair and a boy's narrow-hipped body, opened the passenger door, Vaughan handed a bottle to her. Lifting her chin, he put his fingers in her mouth. He plucked out the knot of gum and flicked it away into the darkness. 'Let's get rid of that – I don't want you blowing it up my urethra.'

Adjusting myself to the unfamiliar controls, I started the engine and crossed the forecourt to the slip road. Above us, along Western Avenue, the traffic stream edged its way towards London Airport. Vaughan opened a wine bottle and passed it to the blonde sitting beside me in the front seat. He lit the first of the four cigarettes he had rolled. Already one elbow was between the dark-haired girl's thighs, raising her skirt to reveal her black crotch. He drew the cork from the second bottle and pressed the wet end against her white teeth. In the rear-view mirror I could see her avoiding Vaughan's mouth. She inhaled the cigarette smoke, her hand resting on Vaughan's groin. Vaughan lay back, inspecting her small features with a detached gaze, looking her body up and down like an acrobat calculating the traverses and impacts of a gymnastic feat involving a large amount of complex equipment. With his right hand he opened the zip of his trousers, then arched his hips forward to free his penis. The girl held it in one hand, the other steadying the wine bottle as I let the car surge away from the traffic lights. Vaughan unbuttoned her shirt with his scarred fingers and brought out her small breast. Examining the breast, Vaughan gripped the nipple between thumb and forefinger, extruding it forward in a peculiar manual hold, as if fitting together a piece of unusual laboratory equipment.

Brake-lights flared twenty yards ahead of me. Horns sounded from the line of cars in the rear. As their headlamps pulsed I moved the shift lever into drive and pressed the accelerator, jerking the car forward. Vaughan and the girl rolled back against the rear seat. The cabin was lit only by the instrument dials, and by the headlamps and tail-lights in the crowded traffic lanes around us. Vaughan had freed both the girl's breasts, nursing them with his palm. His scarred lips sucked at the thick smoke from the crumbling butt of the cigarette. He took the wine bottle and raised it to her mouth. As she drank he lifted her legs so that her heels rested on the seat, and began to move his penis against the skin of her thighs, drawing it first across the black vinyl and then pressing the glans against her heel and ankle bone, as if testing the possible continuity of these two materials before taking part in a sexual act involving both the car and this young woman. He lay against the rear seat, left arm stretched above the girl's head, embracing this slab of over-sprung black vinyl. His hand was raised at right-angles to his forearm, measuring out the geometry of the chromium roof sill, while his right hand moved down the girl's thighs and cupped her buttocks. Squatting there with her heels under her buttocks, the girl opened her thighs to expose her small pubic triangle, the labia open and protruded. Through the smoke lifting from the ashtray Vaughan studied the girl's body in a good-humoured way.

Beside him, the girl's small, serious face was lit by the headlamps of the cars creeping forwards in the traffic files. The damp, inhaled smoke of burnt resin filled the interior of the car. My head seemed to float on these fumes. Somewhere ahead, beyond these immense lines of nearly stationary vehicles, was the illuminated plateau of the airport, but I felt barely able to do more than point the large car along the centre lane. The blonde woman in the front seat offered me a drink from the wine bottle. When I declined she leaned her head against my shoulder, giving a playful touch to the steering wheel. I put my arm around her shoulder, aware of her hand on my thigh.

I waited until we stopped again, and adjusted the driving mirror so that I could see into the rear seat. Vaughan had moved his thumb into the girl's vagina, forefinger into her rectum, as she sat back with her knees against her shoulders, drawing mechanically at the second of the cigarettes.

His left hand took the girl's breast, bis ring- and forefingers propping up the nipple like a miniature crutch. Holding these elements of the girl's body in his formalized pose, he began to rock his hips back and forth, driving bis penis into the girl's hand. When she tried to move his fingers from her vulva Vaughan knocked her hand away with his elbow, holding the fingers securely in her body. He straightened his legs, rotating himself around the passenger compartment so that his hips rested on the edge of the seat. Braced on his left elbow, he continued to work himself against the girl's hand, as if taking part in a dance of severely stylized postures that celebrated the design and electronics, speed and direction of an advanced kind of automobile.

This marriage of sex and technology reached its climax as the traffic divided at the airport overpass and we began to move forwards in the northbound lane. As the car travelled for the first time at twenty miles an hour Vaughan drew his fingers from the girl's vulva and anus, rotated his hips and inserted his penis in her vagina. Headlamps flared above us as the stream of cars moved up the slope of the overpass. In the rear-view mirror I could still see Vaughan and the girl, their bodies lit by the car behind, reflected in the black trunk of the Lincoln and a hundred points of the interior trim. In the chromium ashtray I saw the girl's left breast and erect nipple. In the vinyl window gutter I saw deformed sections of Vaughan's thighs and her abdomen forming a bizarre anatomical junction. Vaughan lifted the young woman astride him, his penis entering her vagina again. In a triptych of images reflected in the speedometer, the clock and revolution counter, the sexual act between Vaughan and this young woman took place in the hooded grottoes of these luminescent dials, moderated by the surging needle of the speedometer. The jutting carapace of the instrument panel and the stylized sculpture of the steering column shroud reflected a dozen images of her rising and falling buttocks. As I propelled the car at fifty miles an hour along the open deck of the overpass Vaughan arched his back and lifted the young woman into the full glare of the headlamps behind us. Her sharp breasts flashed within the chromium and glass cage of the speeding car. Vaughan's strong pelvic spasms coincided with the thudding passage of the lamp standards anchored in the overpass at hundred-yard intervals. As each one approached his hips kicked into the girl, driving his penis into her vagina, his hands splaying her buttocks to reveal her anus as the yellow light filled the car. We reached the end of the overpass. The red glow of brake-lights burned the night air, touching the images of Vaughan and the young woman with a roseate light.

Controlling the car, I drove down the ramp towards the traffic junction. Vaughan changed the tempo of his pelvic motion, drawing the young woman on top of himself and extending her legs along his own. They lay diagonally across the rear seat, Vaughan taking first her left nipple in his mouth, then the right, his finger in her anus, stroking her rectum to the rhythm of the passing cars, matching his own movements to the play of light sweeping transversely across the roof of the car. I pushed away the blonde girl lying against my shoulder. I realized that I could almost control the sexual act behind me by the way in which I drove the car. Playfully, Vaughan responded to different types of street furniture and roadside trim. As we left London Airport, heading inwards towards the city on the fast access roads, his rhythm became faster, his hands under the girl's buttocks forcing her up and down as if some scanning device in his brain was increasingly agitated by the high office blocks. At the end of the orgasm he was almost standing behind me in the car, legs outstretched, head against the rear seat, hands propping up his own buttocks as he carried the girl on his hips.

Half an hour later I had turned back to the airport and stopped the car in the shadows of the multi-storey carpark facing the Oceanic Terminal. The girl at last managed to pull herself from Vaughan, who lay exhausted against the rear seat. Clumsily, she reassembled herself, remonstrating with Vaughan and the drowsy blonde in the front seat. Vaughan's semen ran down her left thigh on to the black vinyl of the seat. The ivory globes searched for the steepest gradient to the central sulcus of the seat.

I stepped from the car and paid the two women. When they had gone, carrying their hard loins back to the neon-lit concourses, I waited beside the car. Vaughan was staring at the terraced cliff of the car-park, his eyes following the canted floors, as if trying to recognize everything that had passed between himself and the dark-haired girl.

Later, Vaughan explored the possibilities of the car-crash in the same calm and affectionate way that he had explored the limits of that young prostitute's body. Often I watched him lingering over the photographs of crash fatalities, gazing at their burnt faces with a terrifying concern, as he calculated the most elegant parameters of their injuries, the junctions of their wounded bodies with the fractured windshield and instrument assemblies. He would mimic these injuries in his own driving postures, turning the same dispassionate eyes on the young women he picked up near the airport. Using their bodies, he recapitulated the deformed anatomies of vehicle crash victims, gently bending the arms of these girls against their shoulders, pressing their knees against his own chest, always curious to see their reactions.