Of course, I appreciate that they are the most significant product that human endeavour has produced. A massive industry fuelled by the liberating dream of escape, of individual freedom, of man-machine-motion. Cars are the most significant organising principle since the mid twentieth century, structuring land, stock markets, employment patterns, and environment. But the things themselves? I'm happy behind the wheel of my wife's Vauxhall Corsa.

So I'm on a business class flight to Detroit looking suspiciously at a cabin full of men reading car magazines. Me? I'm reading a piece on the AOC in the Saturday FT. I'm hoping that somehow I'll be able to glimpse the heart of the military industrial complex amongst the shiny bodywork, gleaming chrome grills and jewel like lights.

A car show is, of course, about cars, but it's also about the dream of the industry and culture that creates them. The cars perfect sheen is hallucinatory as a mirage - and it's meticulously preserved by teams of polishers who remove the publics greasy fingerprints as though wiping down a weapon. This year, despite the ultra confident, self-assured corporate visions lurks the possibility that their dream might vanish. The show takes place against a backdrop of local and international crisis. Motor City has lost thousands of jobs and the brands that defined US car culture are in decline. Globally, the dream is becoming obscured by the clouds of recession, the dust of oil field conflict and looming environmental catastrophe.

The response? Like a dieter tucking into low-fat eclairs, car design is pushing the limit of bigness, fastness, and luxuriousness while simultaneously claiming sustainability as a kind of mantra of self-preservation. Even bull-bar bearing American trucks now come in biofuel flavours - though they are so macho that probably means a tank full of fried food and beer. The new Dodge pick up - launched in cod wild west frenzy with cowboys and a cattle run along Washington Street - makes its own contribution to a sustainable future: 5% better fuel efficiency. Hummers - those extreme mechanical fantasies - response is to make a slightly smaller model which only exaggerated its similarity to a kids mechano-military toy. According to press releases, sustainability can also be a feeling or an aesthetic.

The car show revolves around what's termed 'the reveal': the moment of accelerated strip-tease when the silky drape that hugs a cars contours like the dresses on the girls on the Italian car stands is whipped off to reveal the new model. Once exposed, cameras zoom in pornographically on chrome orifices, folds of steel and the sheen on its buffed skin. These events are carefully scripted and choreographed.

At Land Rover, the build up is so monumental and portentous it sounds like an Imperial Star Ship with Jean Michel Jarre on board with a PA announcement by the same guy who voiced the Nuclear War warnings. Man, it's significant.

It's here that you'll hear phrases like "A diesel powered Super Sports Car!" over a heavy rock sound bed, or a German accent shouting "The Power! The Tradition!" They are as much ideological rallies as they are a way of promoting a particular product.

There are the events too, most of which are baffling. During the introduction of the new Audi TT, Bryan Adams wanders onto the stage for a bemusing acoustic version of 'The Only Thing That Looks Good On Me'. Over at BMW a troupe of satin jump-suited street dancers throw robotic shapes to euphoric trance in a space portal of rings. It's like a ritual dance from the future - lit in the kind of ultra-violet that makes you feel as though you are in geostationary orbit. Quite possibly it's a modern dance interpretation of the stands uber-Tutonic strapline: "More Efficiency".

Each stand sets a scene for the brand and its models. Mini is shiny black and neon, like a 80's nightclub, complete with resident DJ and juice bar. Audi have a stage set version of a high Modernist villa; Dodge have a massive backlit ramshorn logo and moving message sign like a hyped up sports arena; Jeep creates a rocky outcrop with a skeletal Rocky Mountain lodge. Ford is super-brite, lit with a hint of ultraviolet and completely bland. If the Aztecs had had car dealerships, they'd have looked like the Infinity stand (The Temple of Vroom?)

The concentration of brand identity is so saturated that the patchwork of floor materials could be an essay in contemporary corporate aspirations. As it changes from stone flags, to mirrored metallic to deep pile carpet to pseudo grass, via Hessian weave you feel the aspirations and values encoded into floor finish. You can feel this concentrated message encoded beneath your heel.

The activities on the stands are just a brand-centric. Bentley have a craftsman wearing an apron who looks like he came out of the 1950's involved in some intricate work involving hardwoods and leather. Lexus have set up a spa where you can be massaged amongst silver birch trees and executive cars. At Land Rover, an executive club style lounge is filled with piles of culture books: Andy Goldsworthy, Chanel, one of those '100 architect' books, Art Forum, Wallpaper and Monocle and people drinking Guinness.

In a thoroughly un-reconstructed display that only the Italians of Mazzerati, Ferrari and Lamborghini could possibly put on without a hint of irony, girls pout and pose, leaning suggestively across the bonnets of over-powered, ridiculously sculpted cars. It seems like a moment out of time - like pulling a 1970s ready meal out of a freezer.

In an annex, past a security guard, down a staicase and behind a curtain, something else is happening. It's here you'll find the solar powered cars, cars from emerging manufactures, and a selection of pimped-up cars presented by Dub magazine which parody the obsessions with power, presence, technology and luxury.

In a stand that looked like it should be selling strawberries in a lay-by there is a line up of cars produced by Li Shi Guang Ming Automobile Design Co that might well have popped out of a cartoon: Postman Pats van with a Yellow Submarine makeover. They have the most beautiful names: 'A Piece of Cloud', 'The Book of Songs', and the amphibious 'Detroit Fish - which carried the satirical marketing suggestion that it might suit "renowned environmentalist President Bush, ordering this car for his Texas Ranch".

Along with the $2,500 Tata Nan recently announced by Indian manufacturer Tata it is possible that future of cars might deviate from the extreme Anglo Saxon obsessions that have characterised the industry since its origins: an alternative to the mantra of Harder, Faster, Stronger, Better.

Cars in their current form are not inevitable conclusions; they are extreme conclusions of one strand of thought. There may well be other ways to perform the most important role of cars: devices that interpret the cultural idea of journey, that engage with the romance of the open road, and which become the physical manifestation of individual freedom in the landscape.