THIS is not an E-Class. Repeat after me - this is not an E-Class, this is not an E-Class.

The Mercedes CLS may have the same number of doors as an E-Class, but it's important to remember that's where the comparison ends.

You see, the CLS is the product of the German firm's desire to plug gaps - or niches - in the car market, albeit at the premium end.

Niche filling is the latest thing. BMW has successfully achieved it with its X5 sport utility model, while the Scenic has done wonders for Renault's bottom line in the compact people carrier sector.

Another favourite pastime in the auto industry is pigeonholing manufacturers' latest offerings in clearly-defined classes to make the media's comparisons easy.

But that sound you can hear - thousands of scribblers scratching their heads - is a direct result of the CLS' arrival.

It may have a quartet of doors and a saloon-like boot, but it's being pitched as a four-door coup.

Yes, you read it right - a four-door coup. Blame the marketing department, blame the advertising boys - just don't blame the designers.

In profile, the CLS strikes a glamourous, low-slung pose - far more so than its E-Class cousin.

And irrespective of the tale of the tape, the CLS looks bigger and, as such, casts a more distinctive shadow on the road.

At a time when being flash is frowned upon and cars even in the upper premium sector have become more conservative, the CLS (pictured) is a bold sight.

Its curves and creases offer little in the way of substance but plenty of style, while its squat, road-hugging stance hints at a more sporting demeanour than the Merc of choice of German taxi drivers.

With yearly production mooted at a conservative 30,000 units, you won't be stepping from an airport concourse into a CLS anytime soon. And it's unlikely that the car's petrol V6 and V8 line-up will tempt cab drivers out of their oil burners.

No, this is a car for people who are attracted to glamourous-looking cars, but still want something solid and dependable.

For all the smoothness of the CLS 350's V6 motor at low speeds, it can't compete with the 500 V8's superior thrust and deep, urgent engine note.

On paper the figures are closer than you think - 272 horses versus 306 - but on the road the CLS 500's ability to pull enthusiastically from low down and maintain that pace throughout the rev range is impressive. Coupled with the firm's new seven-speed auto gearbox (the 350 is similarly equipped), changes are smooth.

The shift buttons on the back of the steering wheel are especially useful on twisty roads when constantly leaping from throttle to brake pedal would upset the car's balance.

And then there's the ride. While the 350 is suspended by conventional steel springs, the 500 gets an adjustable Airmatic set-up.

If the CLS' driver-centric personality is something of a surprise, so is the car's interior.

Although it follows the E-Class in many respects, it gives off a distinctly hand-finished feel thanks to a noticeable improvement in quality over other Mercedes.

But what Mercedes giveth in one hand it taketh away with the other - namely cabin space at the rear.

Putting the CLS' accommodation into perspective, it falls between the previous and current generation Jaguar XJ.

But let's face it, this isn't a car to ferry passengers around.

Repeat after me - please, Mr Bank Manager, can I borrow £50,000...?

For more information, call Tony Purslow Mercedes on 01256 464050.