It's all about me.
I remember an ad campaign from some time ago in which a practical couple drove a practical car around the city, passing flashy cars populated by people who shouted their idiosyncracies through megaphones: from the sportscar, the bleach-blonde woman declared "I crave attention!" From the oversized sport-utility vehicle, the blow-dried, manicured businessman proclaimed "I have a small . . ." The couple, meanwhile, have branded themselves: in a world of vanity, they are pragmatic and sensible, and fiercely proud of it.
I guess people identify with their cars, and some go so far as to make statements with their cars. I do this myself: the Z from my spandex bodysuit shows through the window of my hatchback, helping me distinguish my Hyundai from every other, and letting people know that there's a geek of the highest order within walking distance of the parking lot. But it strikes me today, having seen this car from behind, that we inhabit a culture predisposed toward the exaltation of the self.