TURIN - If you want a one word description of where European design is headed in the last years of the 20th century you won't do better than diversity.

Diversity, not just through a greater variety of niche models, but also an enormous variance in styling terms, and an increase in technical innovation that is directly impacting design.

To Europe's traditional Big Six - Volkswagen AG, Fiat SpA, PSA Peugeot Citroen, Renault SA, General Motors Corp. and Ford Motor Co. - must now be added the fast expanding BMW AG/Rover group and Mercedes-Benz, which will have the capacity (with the Smart) to build more than 1 million vehicles a year by 2000.

The Japanese manufacturers, too, and especially those who build cars in Europe, realize it's no longer good enough to take a domestic Japanese product, assemble it on the other side of the world, and expect to be competitive. Toyota Motor Corp., Honda Motor Co. Ltd. and Nissan Motor Co. Ltd. chiefs finally are listening to their transplant design studios and planning radically different cars that are aimed squarely at the huge, 15-million-strong annual European market.

Germany's carmakers, led by Volkswagen, are on a roll, although the in-fighting over once traditionally demarcated classes means VW and Mercedes-Benz are now head-to-head, with repercussions neither manufacturer can fully anticipate. Expansion away from historic positioning means stylists at these auto companies are busier than ever. While the VW Group - VW, Audi, SEAT and Skoda - has almost completed its planned reduction from 16 platforms to just four, the number of models grows from today's 39 to 51 by 2001.

Says Chris Bangle, the 41-year-old American head of design at BMW: "German cars are very severe and serious, and it has paid off. The seriousness in design is reflected in the cars, whereas Italian cars are sculpture on show."

Will the VW Group succumb to the same trap that befell GM during the '80s, by making too many look-alike cars? When the Audi A4/A6/VW Passat share the same mechanical underpinnings and a restricting number of design hardpoints, can they retain enough individuality of design and driving character to justify Audi's premium price policy?

"There's one key difference between VW and GM," says Mr. Bangle, "the marques are nationally linked, and the consequences of how they work on these differences are the key factor."

The effect of a market that's dividing between the prestige brands and the high-volume makers, and thus leaving little middle ground, is profound. Marques such as Mercedes, Audi and BMW are taking a dominant percentage of the executive class, where once the Ford Granada/Scorpio, Opel Omega, Peugeot 605, Renault Safrane, Alfa Romeo 164, Citroen XM and Lancia Kappa achieved justifiable volumes.

Fiat now makes no attempt to compete, having axed the Croma, and independent observers wonder how PSA can justify development of the 605 and XM replacements when between them they struggle to sell 20,000 cars a year. Only Volvo seems seriously able to buck the trend to the Germans, while Ford intends to rely upon the magic of Jaguar.

"The Germans do the three-box sedan very well," says Peter Davis, a former Art Center College of Design classmate of Mr. Bangle's and now the head of Fiat's Centro Stile, "The others know they can't go head-to-head (with the Germans), so they're looking at alternatives. Renault wants to mix the concept of a three-box with an MPV for its Safrane replacement by giving it a high floor and removable, individual seats. Flexible interiors is now the bandwagon and everybody is getting on."

The concept of GM's Opel Signum show car not only establishes a new styling trend for GM but, by combining the virtues of a station wagon with a luxury sedan, effectively sets out to deliver a similar concept.

Ford's Escort replacement - believed to be called Ikon and due to break cover at September's Paris auto show - isn't as exaggerated as Mercedes-Benz's troubled mini-MPV A-Class, but you will be hearing a lot about "package efficiency" from Ford in the next six months.

The new Escorts are significantly taller than the models they replace, to bring more spacious interiors and increase their versatility. Taller mainstream models are inevitable: Toyota's European-designed Funtime and Audi's all-aluminium A3 rival for the A-Class lead the rush.

Rivals for the hugely successful Renault Megane Scenic - now the best-selling individual model in the five-model Megane range - that bring the MPV concept to Europe's best-selling class arrive in '98/'99 with models from Fiat, Ford, Opel, VW, SEAT and Peugeot and Citroen.

Renault's tiny Twingo mono-volume hatch has no current rivals except for Ford's quirky Ka, but that's sure to change with Citroen's unashamedly retro revival of the 2CV and its Peugeot 107 brother under the skin. The Twingo replacement is even more outrageous; it's said to have rear-facing seats just to add to the divergence in packaging.

No longer is there a generic Euro-look to the front end of Europe's most popular models. In the early '90 it was nearly impossible to recognize head-on an Opel from a Ford from a Peugeot or a Renault, due to the similarity of the headlights separated by simple bar grilles. But that era's over.

"The feminization of design," claims Mr. Bangle, "means we are able to express our inner emotion in the design of cars. There is a trend away from the austere, to put more life in to cars, to show the dynamism of design, so cars are no longer cold and reserved."

"There is an increasing concentration on extreme detail in design," says Mr. Davis. "The headlights of a car now take as much design time as all the rest of the car. They are incredibly precise instruments, and their quality can be drastically influenced by innocently doing something wrong."

Says Mr. Bangle: "The headlights of a car are like the eyes of a woman, the part of the face you look at first. They should sparkle like jewelry and produce a high-tech optical look."