MOTORING / It's official: size doesn't matter: The concept is what counts in the new generation of vehicles, writes Roger Bell

VOLVO MAN is facing a dilemma. Does he graduate to a 940 estate - staid, safe, practical, prestigious - for his growing family, or spurn convention for trendier transport? A decade ago, he had no choice. Today, he could opt for a more versatile multi-purpose vehicle (MPV) like the Renault Espace, precursor of a new breed of socially acceptable van-like cars that Ford, Fiat, and Peugeot, among others, plan to imitate.

Open-plan people-carriers like the new Nissan Serena are helping to change the face of private motoring. So are micros, coupes, convertibles, roadsters, supercars, pick-ups, off-roaders and other cross-pollinated hybrids. Sales of some specialised models are rising steeply, despite the recession.

People who still categorise cars by length and engine capacity - small ones for the workers, big ones for the nobs - have missed the message. Elvis is dead, cars are changing. Design diversity is leading to an almost infinite number of variations. Vertical marketing, industry-speak for selling cars by rank, is passe. Now cars are being distinguished by type and concept rather than size and status.

Small-volume specialist cars exist in practically every manufacturer's model range. The Audi 80, for instance, is for most buyers a straightforward four-door, front-drive family saloon. Nice but not special. Derived from it, however, is the exclusive 80 S2 estate with turbo power, six speeds and four-wheel drive. Enter the hell-raising hold-all.

Helmut Werner, deputy chairman of Mercedes-Benz, sees specialisation as more than a passing fad: it is the recipe for survival, especially where the pace of change is being forced by environmental factors - traffic congestion and city pollution, for instance. 'The division of the car market into luxury class, medium class and small is becoming less and less meaningful,' he says.

A small, low-pollution city runabout that can be parked on an ecu does not fit with Mercedes' traditional luxury-car image. Such a mini Merc is under development, however. So is an MPV multi-seater. As if to confirm the way ahead, arch-rivals BMW are to reveal a prototype city car, with motorbike power and automatic transmission, at the Geneva show in March. According to Herr Werner, the role cars play, as defined by the shape and style of their bodywork (and the number of driven wheels), is becoming more important than size, power and performance. Jaguar's XJ6 estate prototype indicates similar lateral thinking.

Even the big, high-volume manufacturers are trying to get into a niche - or lots of them. Ford, for instance, is planning to launch a coupe (the Probe, taking over where the Capri left off), as well as an MPV and a leisure-orientated off-roader known as the Maverick. Expensive options like a V6 engine and all-wheel drive will zap the most costly versions of the Mondeo (the Sierra's replacement) deep into the specialist sector.

Rover is too small to compete on equal terms with the industry giants, so its speciality is to specialise. The Honda-based 200/400 series, while covering Ford's comparable Escort/Orion, has spawned two-door coupes and convertibles as well as three and five-door hatchbacks, and four-door saloons. In its 220 Turbo coupe, Rover fields the cheapest 150mph car on the market, if not the best. Ironically, the oldest car in its range - the evergreen Mini - has matured into the sort of small-volume cult car that other manufacturers envy.

Japan's empathy with the Mini is perhaps linked with its flair for identifying and exploiting small market sectors. It's a shame that many of its speciality models - like the Honda Beat (a baby mid-engined sportster), Honda Today (a nippy new micro) and Nissan S Cargo (a fun van) - are obtainable in Britain only through the back door as personal imports. Every Mazda with an X in its name - including the Xedos (a compact six-cylinder luxury car), MX3 (a super-refined coupe) and the RX-7 (Porsches beware) - is a speciality.

The Volvo estate driver has several MPV alternatives; Espace apart, there is also the Nissan Serena, Toyota Previa and Mitsubishi Space Wagon, not to mention rival seven-seater estates. Most other user-choosers have an even wider choice. Given that 70 per cent of all journeys to work are made by car, millions of people must be commuting in something which is less than ideal for the job. Although Renault's mould-breaking Twingo is rather more than a city nipper, it looks set to become the darling of Paris. Les Anglais will have to wait for right-hand drive. Meanwhile, any small, nimble automatic is likely to suit the single urbanite better than the typical mid- sized hatchback that many of them drive. Of the fringe micros - cars like the Fiat Panda, Daihatsu Mira and Subaru Vivio - none is as practical as Nissan's Micra automatic. Specialist cars are not necessarily better cars.

For the high-mileage business driver, a frugal diesel is the obvious choice. Some are capable of extraordinary feats - like covering 1,000 miles on a tank of fuel. Others are fast and entertaining; Citroen's ZX TD is a cracker. Diesels practically span the market spectrum, from Rover's Metro to Mercedes' 300TD.

Sports-car addicts have never had it so good. Motoring as an 'experience' is a cornerstone of horizontal marketing, according to Mr Werner. How this squares with growing congestion is unclear. It has, though, a lot to do with fun cars, and there is no shortage of them.

Stylish, soft-centred convertibles - Ford Escort, Renault 19, Rover 200 - are mostly driven, when new, by women, according to market research by Renault. Rumbustious tearaways epitomised by TVR's Chimaera are largely a male preserve. In between, there is something for every taste, from mild to vindaloo, from Mazda MX5 (delightful open two-seater) to Honda NSX (a sort of Japanese Ferrari). Not that the Japanese are having it all their own way, with coupes as bewitchingly good as VW's Corrado VR6 opposing them. MG is back next month, though only as a modernised MGB called the RV8; and Porsche is back on track, if its Boxster show car is an accurate pointer to future models.

It does not end there. New government regulations that exempt small-scale manufacturers from prohibitively expensive type-approval procedures have cleared the way for kit-car manufacturers to be able to sell completed, turn-key sportsters in limited numbers against establishment competition. Westfields and Caterhams, progeny of the old Lotus Seven, are certainly an experience for those who like their motoring raw.

You can be sure there are no such cars in Mercedes-Benz's script.-

(Photograph omitted)