It is curious that within the confines of Cronenberg’s cinematic experience, it was decided that Ballard would concern himself with replacing his crash vehicle with one exactly like it.  Within the film, Ballard becomes interested in only two cars - his own, which he replaces with a like model, and Vaughan's, which ultimately offers him the ability to drive a real crash vehicle. 

In the novel, as illustrated in the opening paragraph of this chapter, Ballard initially has a broader interest in cars.  Catherine and Renata have apparently been trying to dissuade him from driving at all, but the visit to his crash site in the previous chapter is still festering in his mind. 

As are the memories of the death of Remington's husband.  Ballard thinks of the dead man quite often, or rather, he remains conscious that he has brought about the death of a man.  This element is ignored in the movie.  However, in the writing, JG Ballard uses the death of the man as a suggestion for Ballard to think about his own death, and what that would mean. 

Ballard has already become obsessed with his own crash site, with the death of Remington's husband, and his role in it.  However, he is using it as a springboard for his imagination rather than for the morose.  Rather than simply reliving this incident, he uses it to project accidents in different cars, with different victims, and different sets of wounds.  It's an interesting point, because Cronenberg chooses to (mostly) show the transformation of sexual desires through the coupling of characters, rather than simply having Ballard go through variations of his own accident.  By omitting these constant visits to the crash site, we are robbed of a sense of place, of the full impact of this one vital event.

Ballard's character is further fleshed out by an example of promiscuity.  Sitting in a rental car, he picks up a prostitute and takes her to the top of an airport car park for sex.  As has been hinted at earlier in the novel, Ballard's relationship with Catherine is not entirely ideal; with suggestions that sexually they've become rather bored of each other (albeit with Catherine's interest awakened since he'd sculpted his body with an accident). 

The sex in the car fits in with Ballard's fantasies around his own life.  The new rental car he is driving had been used by a television studio, and he spends time reflecting upon the fictions it must have participated in, the roles of the actors that had driven it, and what memories lay dormant in the dashboard and seat covers.  As part of his own day dreams, he has become an extension of these fictions.

His sexual encounter is interrupted by two events.  Firstly, there is a minor accident on the road beside the car park.  The police arrive, and this distracts Ballard who eventually casually directs the prostitute back to his penis.

The second interruption is the recognition that he is being watched, and indeed, photographed.  This is his next encounter with Vaughan.  It is not clear if Vaughan has followed Ballard here, or whether he simply hangs out in this spot because he knows it is a location used by drivers and prostitutes.  Is it a coincidence that this is the perfect place for him to watch variations of cars and sex?

In the movie, Vaughan's background is rather vague, with Remington delivering one line which must substitute for what we find in the novel:  "When I first met Vaughan, he was a specialist in international computerized traffic systems. I don't know what he is now."

This tantalizing glimpse into whom Vaughan was, is set aside for who he is.  However, in the novel we get more information.  We not only hear about Vaughan's previous work and his educational background, but we also get details of the accident that has led him to the essence of Crash.

"..this was Vaughan, Dr. Robert Vaughan, a one-time computer specialist.  As one of the first of the new-style TV scientists, Vaughan has combined a high degree of personal glamour - heavy black hair over a scarred face, an American combat jacket - with an aggressive lecture-theatre manner and complete conviction in his subject matter, the application of computerized techniques to the control of all international traffic systems..........  he was saved from being no more than a pushy careerist with a Ph.D. by a strain of naive idealism, his strange vision of the automobile and its real role in our lives......  All too clearly his face and personality still carried the memory of that impact, some terrifying collision on a motorway in the North when his legs had been broken by the rear wheels of a truck."

It seems that in many ways, Vaughan's car obsessions had been part of his life for many years, transformed by an accident that had robbed him of his rugged good looks, a career, or a desire to continue as he was.

In the movie, we don't get any context for Vaughan, of how he became the leader of the group of misfits.  Like God, he just "is", and it takes a leap of faith to follow him.  However, with the information in the novel we can begin to empathise a little more, to know that he was academic and not a little famous (a celebrity) himself.

We also learn more about the car Vaughan drives, another point lost within the movie.  In the novel we read:  "This was a ten-year old model of a Lincoln Continental, the same make of vehicle as the open limousine in which President Kennedy had died."

In the movie, this connection between the celebrity death and the car that Vaughan drives is given rather obliquely, and almost in passing.  While driving down the road, the following exchange takes place:

"VAUGHAN
No, I mean a crash with a history. Camus' Facel Vega, or Nathaniel Nest's station wagon, Grace Kelly's Rover 3500. Fix it just enough to get it rolling. Don't clean it, don't touch anything else.

JAMES
Is that why you drive this car? I take it that you see Kennedy's assassination as a special kind of car-crash?

VAUGHAN
The case could be made."

This is a clever way of addressing the fact, but it gets somewhat lost with the mention of other famous deaths.  Vaughan's dream of driving an actual accident car is kept at bay, it appears, by his ownership of this replica vehicle.  The vehicle also becomes important to Ballard and Catherine, as though it were the source of the Crash infection, passing along the highways like the plaque.