The purpose of the SLR is to impress the hell out of wealthy folk and girls. The first inklings of its design were seen at the Frankfurt Motor Show in 1999 with the Vision SLR.

Designed partly in tribute to the 1955 SLR racing car, the space-race design was quickly adopted for Mercedes' SL and SLK sports models. In photographs, the SLR, SL and SLK are understandably confused, but in the flesh there is no doubting which is which.

In fact, it is the huge SLR that looks the least visually balanced of the three, although the drophead is much better looking than the flashy coupé, which has been all but dropped from the range.

Mercedes says it will produce the convertible and coupé in batches, but reckons it will only be making the former model for the foreseeable future. In a car-making era where production speed is everything, the hand-made SLR is profligate. In Sunderland, Nissan can assemble a new Micra in fewer than nine hours, yet the SLR takes a total of 1,000 hours, or 125 working days, to produce an SLR; it takes 23 hours simply to paint the car.

The SLR looks even better when the pleasing simplicity of that carbon-fibre shell (or tub) can be examined. This resin-encased material is strong and light, but it can be as fragile as peanut brittle when strong bending forces are applied to it.

For that reason Mercedes said it could not make a drophead version of the coupé and pass modern crash and roll-over tests. The company then invented a bonded steel and carbon-fibre windscreen surround that will take the weight in a roll-over.

The engine is carried by twin cast-aluminium frames, which more resemble sculpture than conveyance, and bolt directly to the tub. In front of the engine are twin carbon-fibre cones jutting out like Madonna's Jean Paul Gaultier bra. The sheering resistance of these thick sections absorbs the forces of a front impact, as each section collapses in on its neighbour.

The trouble is that the carbon fibres are still held together with resin and this has all the heat-resistant qualities of Cadbury's Dairy Milk -- especially when you are talking about the 950C temperatures reached by the exhaust catalysts. Fortunately, the original 1950s SLR design comes to the rescue. Distinctive side exhausts allow the exhaust and engine heat to be ducted out of the side and through bonnet vents before it reaches the carbon-fibre bulkhead.

The exhaust cats are cooled with convection via holes in the heat-resistant chimneys, which vent through the bonnet and cause the driver's view to shimmer like that of a parched desert explorer.

The engine is a time-served three-valve V8 displacing 5.4 litres, with its low-down pulling power augmented by a screw-type supercharger bolting extra air into the cylinders at low revs. This AMG unit is quite long in the tooth. In fact, it's soon to be superseded in its sole other application, the SL55, by AMG's remarkable 6.3-litre V8. Even so, it's a pretty effective mill, giving 626bhp at 6,500rpm and a remarkable 575lb/ft of torque from 3,250rpm to 5,000rpm. The gearbox is an unremarkable five-speed auto with paddles behind the steering wheel to change gear manually.

The interior is well finished. There isn't a lot of room, but sensible compartments help. Thanks to the folding hood mechanism the boot is smaller than the coupé's, but large enough for a few weekend bags.

The hood is almost a folding hard top as, to prevent ballooning at speed, Mercedes has bonded the fabric to aluminium formers underneath and employed three bows between them. It's only semi-automatic as Mercedes claims a fully automatic folding soft top would add an extra 13lbs. There are endless trim choices: 12 exterior and 12 interior colours, two qualities of leather, six driver-seat sizes and five for the passenger.

Getting in past the scissor doors provides its own set of problems. Once inside, you turn the key and lift a cheap-looking cover on top of the gear lever and press the starter button. That's when you really know what this car is like. It's melodic and deafening and completely at odds with the high-tech nature of the rest of the car.

This prehistoric monster is amazingly well behaved, trickling gently out of the car park, but there is a sinuous quality to the steering as the engine's vibration is transferred through the bodyshell. Power dominates the experience.

There is so much pulling power that you never need to extend the engine by manually overriding the transmission. Pull out to overtake and you find yourself backing off the throttle so as not to blow other cars off the road. While the power is addictive, sadly the handling never quite lives up to the engine's prowess.

That informative steering ceases its flow of information as soon as the SLR speeds up. The steering rack and pinion is also far too highly geared, so the SLR feels flighty, and there is absolutely no indication of how much grip those 9.6inch-wide front tyres have. On wet German country roads this six-and-a-quarter-feet wide car felt like a complete handful.

The SLR's stiff bodyshell helps to give almost instant turn-in and an alacrity which, compared to a Maybach 57S, makes it feel like a ballet dancer. But the abiding impression is of serious weight and little sensitivity.

Try exploiting this car on a public road and you will join well-publicised celebrity owners, red-faced and in a ditch. By contrast the Mercedes SL65 is bendier, but with almost the same performance -- and it's €350,000 or so cheaper.