World cars will be bland, because they will have to cater for so many different people. Great cars of the past reflected national cultures and national prejudices. The upshot was machines of greatly varying appearances and abilities - and, sometimes, works of true genius. These instances of greatness spurred other car makers, and thus improved cars in general.
Without the national foibles of the Italians, the French, the English or the Germans, we never would have had the Fiat Topolino and 500, the Renault 4, the Mini or the Mercedes S-class.
Those little Fiats of the Thirties and Fifties were the world's most space-efficient and technically ingenious small cars, until the Mini came along in 1959. They were tiny for the wholly practical reason that old Italian towns tend to have narrow roads. Petrol in Italy has always been expensive, so they had fabulously fuel-efficient engines; and they were ingeniously light, saving materials and more fuel.
Equally, the rough roads and the peculiar needs of the strong agricultural sector led to the French car industry developing unique engineering skills: pave and peasantry equals comfortable suspension systems and hatchbacks.
Andre Citroen, arguably the most far-sighted car engineer of all, developed the 2CV so that it could drive across a ploughed field without breaking any eggs carried in a basket. It not only had wonderfully absorbent suspension, but was also versatile (seats could easily be removed to carry small livestock or tools), cheap to repair (simply unbolt a damaged wing and bolt on a new one), light (an air-cooled engine made partly from aluminium) and fuel-frugal. There is no small car today which is as cheap to own, as versatile, as tough or, around town, as comfortable.
The other great seminal French car of the time, the Renault 4, was equally practical and tough. It was a cross between a hatchback and a small estate car, and in many ways a harbinger of both.
Britain's class system gave the world its most regal car (the Rolls), a system of badging (L, GL, GLX, etc) which helped, at a glance, to determine the class of a driver even if the basic car were the same, and the leather-and- wood cabin which was the mark of a gentleman's conveyance but is now merely the mark of all Rovers.
The Suez crisis, and the subsequent threat to our petrol supply, helped give us the greatest small car of all, the Mini. Britain in the Swinging Sixties gave the world the Jaguar E-type - a thrusting, sexy, aggressive car, completely in tune with its rebellious times.
Once Germans started to earn enough money to buy something better than Beetles, they began building the world's best big saloons: Mercedes and BMWs that whisked along big businessmen and big families reliably, comfortably and quickly. The Germans were the first to build motorways without speed limits, so it is no wonder their cars were fast, streamlined, safe and well- engineered.
American cars were big because the country has the fuel and the space; and because the Americans have long associated size with status. The bigger the car, the greater the kudos. American cars were also the most extravagantly styled: big chrome mouths, big chrome fins, extraordinary colours. Americans have always liked to wear their wealth.
The world car will change this marvellous multiplicity of cultures, of course. Indeed, it is already happening. American cars are getting smaller; Italian cars are getting bigger; French cars are less practical and less comfortable; British cars have less class; Germans are starting to drive more slowly. Some national traits do survive, despite the increasing globalisation of the car business. The French (Peugeot and Citroen, in particular) still make the best suspensions in the world. The British design the best cabins. The Japanese make the best engines (a consequence of their skills in motorcycle engineering and mass production). The Italians come up with the most imaginative designs.
But slowly, surely, those differences are being ironed out. The big car companies continue to swallow the small ones (new Jaguars are being developed by Ford, new Saabs by GM). International engineering solutions are being applied to national problems (which makes about as much sense as individual countries being governed by the United Nations). Flair and individuality are being replaced by corporatism and commercial sense - hang any sense of culture, or national creeds.
Mainstream cars will get more boring, as Toyotas start to look more like Fords or Rovers or Renaults. And they will not just look more boring: their engineering will be less different, less innovative.
The recent planned merger between Renault and Volvo was symptomatic of these sad times. Are there two more disparate companies in the world? I ask you. Yet perhaps there is hope. Amid various remonstrations (particularly from the Swedes) against national characteristics and interests being neutered, the deal fell through.
The break-up was probably commercially damaging to both firms. Yet if it means we get another generation of Clios and Twingos and Espaces and Alpines, before Renault is finally neutered in the name of international business sense, it cannot have been altogether a bad thing.