Mercedes-Benz: SLK 200

This convertible boasts a unique electro-chromatic roof. But it's the simple stuff that it does best

This new SLK looks like a proper sports car, powerful and poised, high on visual thrust, ready to blast your hair out by the roots.

Already that's a departure, for none of the foregoing necessarily applied to previous representatives of Mercedes-Benz's small sports car line. The cars might have looked sporty but they tended to be quite meek once you got to drive them. Either that, or over-larded with the refinement of V6 engines and automatic transmissions.

There have been exceptions, usually with the AMG letters after the name that signify Mercedes's in-house tuning company, but even they haven't quite hit the mark.

My favourite version of the outgoing SLK range was the most basic, the four-cylinder one with the supercharger and the manual gearbox. It was the SLK that best did what a sports car should do, which is to do exactly what you ask it when you ask it, and to do it with enthusiasm.

Now I'm driving the new incarnation of the entry-level SLK. This time its 1.8-litre, four-cylinder engine is turbocharged, impressively frugal and makes 184bhp (a 204bhp version, called SLK 250, is also offered), but as before it sends this power to the road via a six-speed manual gearbox and rear-wheel drive. I'm scything along roads threaded between Tenerife's volcanic mountains, and I'm having an unexpectedly good time.

First, though, let me tell you about the SLK's major innovation, the one the salespeople will be falling over themselves to tell you about. Meet the Magic Sky roof. All three SLK generations have had solid, folding roofs which turn the car into a proper coupé when closed. Indeed, the SLK reinvented the coupé-cabriolet idea for the modern age.

But this time the roof, made from aluminium, magnesium and polycarbonate, is especially special. As an extra it can have a glass panel able to let in the sun and make visible the clouds, or seal them out with opacity, at the touch of a button. It does this by applying an electric current to the tint in the glass, which alters the alignment of its molecules to let light in or not. Infra-red and ultra-violet radiation is always blocked.

As one who usually pulls the sunblind across a panoramic glass roof, Magic Sky is a bit lost on me. But there are many who will like it. For me, though, to see the sky should be also to feel the air under it, which means the roof should be folded away. Should my passenger complain at the draught, then there's Airscarf (launched with the previous SLK) to warm her neck from vents in the headrest.

I tried the Magic Sky roof in an example of the grandest SLK, the V6-engined 350 with 306bhp and the full gamut of sport suspension and Direct Steer options. And I had to eat some of those earlier words because it sounded great, had a crisply-responding seven-speed automatic with an excellent paddle-shift manual mode, zoomed up mountain roads with vigour and felt very alert with that trick steering system. This has a quick, high-geared response around the centre for maximum response with minimum steering-wheel movement, but is lower-geared towards the extremes of turning to make parking less strenuous.

I can't quite see the point, actually, given that the power steering is itself supposed to take the effort away, but the effect is of an artificially heightened "pointability" at speed which helps mask the weight of the big, heavy engine. Changing to the SLK 200 shows the difference; inherently lighter, it doesn't need these tricks and feels rather more natural and progressive in the way it takes corners. There are standard and sport suspension alternatives, of which the latter better suits the SLK's aura without proving harsh over bumps.

The turbocharged engine has a crisp exhaust note and pulls vigorously enough to give a good time, and the manual gearbox is enough to make the SLK a credible sports car. This 200 version is the only SLK available in such a form, which makes the decision easy for me. I could bond properly with this car, explore the forces acting on it and within it, feel what it is telling me, and never before have I enjoyed a Mercedes-Benz SLK as much. That at £29,970 it's the cheapest version in the range makes me feel even better.

The Rivals

Audi TT Roadster 2.0 TFSI Sport: £29,110, 211bhp, 156g/km

Slightly smaller than SLK, front-wheel drive, handsome and lively. Still looks crisp and desirable, has soft-top roof.

BMW Z4 sDrive23i: £30,405, 204bhp, 199g/km

Has coupé-cabriolet roof like SLK and a ludicrous name (sDrive simply means rear-wheel drive). Less of a pleasure machine than SLK.

Porsche Boxster: £36,572, 255bhp, 221g/km

Cheapest Boxster looks expensive in this company but it's also the fastest. Mid-engined layout gives race-car balance. Roof is soft-top.