Mercedes magic is no pie in the sky.(Features)

Byline: CHRIS RUSSON

THE most convertible convertible will be opening up for business in time for summer as Mercedes launches its latest roadster.

The third generation SLK can be an open top, hard top or even a glass top - and in the latter guise it can be had with world-beating technology.

When it arrives in June the new SLK will be the first car ever to feature a glass roof with an electronic tint where at the touch of a button it switches from light to dark.

Mercedes calls it Magic Sky Control and while not cheap as a pounds 2,000 option it is a powerful tool which can significantly alter the mood in the cockpit. Switched off it lets the light through as with any other panoramic roof.

Push a switch in the roof lining of the windscreen and in an instant the glass changes to an aqueous dark blue hue filtering out virtually all of the sun's UV rays and creating shade inside.

The science is similar to that of photochromatic lenses but with Magic Sky the tinted elements in the glass become aligned when an electronic current passes through.

The latest SLK can also be had with a more conventional glass roof or - as with the previous models - a metal top. Whatever version, all three roofs fold away into the boot in less than 20 seconds for pure open-top, two-seater enjoyment.

Roof up or down the cockpit of the SLK has an intimate feel with a hi-tech instrument binnacle flanked by a display screen and a bank of switchgear.

A smart touch is an analogue clock which sits in a cowl on the top of the dashboard.

At night, ambient lighting picks out the detail inside creating a warm glow. The entire effect is smart and swish.

The SLK has always been something of a style statement for Mercedes since the original 'baby' roadster arrived in 1996 complete with its supercharger power bulges in the bonnet - a flashback to the mighty Mercedes racing cars of yesteryear. The current version took some of its inspiration from the pointed nose of the exotic McLaren Mercedes SLR, a feature it shared with the Mercedes Formula 1 car.

The new one harks back to the 190 SL of the 1950s with a broad bonnet, upright grille and angular headlamps all set off with some pronounced air vents in the front skirt and in the wings - and in one colour scheme, a sensuous metallic gold called pearl beige, the retro feel is quite eerie.

That touch of dj vu is tempered with the nose being similar to that of the awesome AMG SLS gullwing and the current CLS super coupe - a relatively flat face but styled cleverly to make the car more aerodynamic than its predecessor and in profile there is quite a bubble look to the roofline.

If the SLK of old was ever thought of as being one for the well-to-do girlies then now it has gone macho with plenty of muscle.

In the name of efficiency turbo charging has replaced the supercharged Kompressor engines and 1.8-litre four cylinder units power the new SLK 200 and 250 models.

In the 200 the engine develops 184bhp with the 250 pushed to 204. Both are available either with six-speed manual or seven speed auto boxes, and it's the latter which gets the best from the car.

Now fitted with an aluminium bonnet, front wings and doors to reduce weight, the SLK 200 makes 0 to 60mph in seven seconds and can average 43 to the gallon with CO2 emissions of 151g/km - and the power delivery is magnificently suited to British roads.

Either gearbox is slick and punchy and there is a great blend of growl and turbo howl under acceleration.

As a manual it is priced from pounds 29,970 with the auto costing pounds 31,490.

The marginally quicker (half a second 0 to 60) and slightly thirstier 250 will be auto only to start with and priced from pounds 35,710. A manual version will be on the way later in the year.

The most powerful SLK 350 makes use of a 3.5-litre normally aspirated V6 and delivers even more sound as well as performance.

All three engines are direct injection and with either transmission use stop-start devices which combined help to improve fuel economy by more than 25% compared to the previous models.

The V6 can be had only with the auto box and with AMG Sport body kit and is best with an optional handling pack which includes automatic dampers.

With a 0 to 60 time of around 5.5 seconds its is nudging into the top echelon of sports cars and at pounds 44,115 is pitched against the Porsche Boxster and BMW's M machines.

The AMG styling kit and additional trim including leather seats and 18-inch alloys is also going to be available on all versions of the SLK which will be badged Sport models and priced at pounds 4,000 more.

Decked out in such fashion the new SLK brings a touch of finesse to roadster motoring which, with the folding metal roof and AirScarf seat warmer, is a genuine 365-day-a-year car.

The AirScarf neck-level hot air feed from the back of the seats was an innovation on the last generation SLK and true to form the new model has a few clever features up its sleeve including internet connectivity if required and a wiring system which enables the car to be fitted with a Map Pilot portable navigation system.

Map Pilot has been developed specifically for Mercedes by Becker as a pounds 500 option in place of the full blown Comand telematics system which can cost more than pounds 2,000.

Like most portable navigation systems it can be preprogrammed and updated from a home computer but when slotted into the car it is operated via the factory fitted controls and display screen.

Standard kit on the new SLK includes a driver drowsiness monitor while anti-collision devices can be fitted along with active cruise control.

A camera-activated system which flashes up changes in speed limits onto the dash can also be fitted, although all versions of the car have speed-limiting devices and cruise control.

With the new model the SLK has grown to such an extent it is almost breaking into the territory which has been the preserve of the larger SL sports cars - and at 335 litres the boot of the SLK is only a fraction smaller.

But that is by no means game, set and match for the SLK. Mercedes will be playing its trump card later in the year with the introduction of a high performance diesel version.

This will use the 2.1-litre engine already used in the C and E-Class models and it is likely to give the SLK even more thrust with fuel economy in the 60s.

Without a doubt, Mercedes is poised to turn the roadster market on its head with the latest SLK.

Every aspect of this car is fashionable and desirable - and with the diesel on board it will be capable of satisfying a whole new type of two-seater fan.

CAPTION(S):

* The AMG styling kit and additional trim including leather seats is also going to be available * The new Mercedes SKL will be the first car ever to boast a glass roof option