Chrysler's road-to-Damascus conversion came when they embraced the theories of a fashionable French medical anthropologist, G. Clotaire Rapaille, and the result of his work - the PT Cruiser - is unusual enough for even the Wall Street Journal to hail it as a kind of corporate miracle. Rapaille's system of "archetype research", developed from his early work with autistic children, does not do away with focus groups: it merely makes them do different things. Participants lie on floors in darkened rooms with soft music playing, making up "stories" about the designs they are shown. Rapaille prefers them to be in an almost trance-like state, leaving their intellect in neutral while putting their instinctive reactions into gear. Out of a welter of results that Chrysler's management initially found vague and confusing, the design of the PT Cruiser (PT stands for Personal Transportation) changed from being like a big toy into something meaner: a Mad Max vehicle, rugged and a touch sinister. It seemed that people felt that the world outside was a dangerous place: they wanted a big bruiser of a vehicle they could feel safe in. You could describe this mood as "Volvo syndrome", but the PT cruiser has added steroids.

Mad Max tamed
Rapaille has worked with other big corporations such as Kellogg's and Procter and Gamble, so presumably his methods are deemed to work. Stripped down to basics, he appears to be telling these global companies to trust more to instinct - but doing so in a way they understand, and which their shareholders will approve. Others disagree with such marketing psycho-speak, and question the need for extensive public involvement in the design process. The highly successful designer-manufacturer James Dyson, for instance, comes from a tradition of British inventiveness that believes simply that if a product is good, it will sell: distinctiveness is a key part of his strategy. "You can't have customers designing your product for you," says Dyson. "We have focus groups, but I take a perverse delight in ignoring them. Customer criticism is much more valuable." Dyson points out that one of the most boring British cars ever - the Hillman, later Chrysler, later still Talbot, Avenger - emerged from focus groups while one of the most appealing and enduring, the Mini, was the creation of one man, the late Sir Alec Issigonis.
As companies combine to form ever fewer and larger global manufacturing groups, a basic car structure can be made to wear lots of different sets of clothes. Volkswagen, Audi, Seat and Skoda are all the same conglomerate, along with Lamborghini and Bentley. Ford owns Volvo, Jaguar and Aston Martin, General Motors owns Vauxhall and Saab, Proton of Malaysia owns Lotus, and of course BMW owns both Rover and Rolls-Royce. Even otherwise unconnected car companies form joint ventures to pool costs. Moreover, new computerised design tools allow you to move from concept to showroom metal in a very short time. A cheeky little Ford Ka, for instance, is adapted from a staid Ford Fiesta. A lovable new-generation Volkswagen Beetle is no more than a dressed-up Volkswagen Golf. The new, much-hyped Jaguar S-Type tries to look like the Jaguar Mark II, the quick-getaway car beloved of 1960s cops and robbers - and therefore possessed as an ironic reference by Inspector Morse. From the front, the new Jag pulls it off. The curve of its roof, the shape of its windows, the leather-and-walnut interior, are also right. But at the back, it goes all wrong - there's a oversized boot for the American market. And it shares its underpinnings with an American Lincoln.