First look: McLaren flips Benz SLR’s wig

IT WAS only a matter of time before Mercedes-Benz and its Formula One partner McLaren delivered a topless version of what was the world’s fastest production car.

Four years after the SLR McLaren supercar’s release, however, the appearance of the Mercedes-Benz SLR McLaren Roadster still comes as a surprise.

Like the coupe upon which it’s based, which in 2003 officially became the world’s fastest production car, the drop-top SLR will be built in left-hand drive guise only, at McLaren’s F1 factory in Woking, UK.

To be available in limited numbers globally from September this year, the roofless SLR retains the coupe’s gullwing doors and, more importantly, its carbon-fibre reinforced plastic (CFPR) body structure, allegedly making the SLR roadster torsionally as rigid as its fixed-roof stablemate.

In fact, Mercedes-Benz says the F1-style carbon-fibre technology employed in the open-top SLR’s monocoque chassis was specifically developed to offer "low weight, exemplary energy absorption and, therefore, extremely high occupant safety as well as a degree of torsional stiffness hitherto unattained in open-top vehicles".

Two aluminium engine frames aside, the exclusive use of CFRP for the SLR’s bodyshell is claimed to result in ride characteristics "of the kind otherwise found only in closed-top super sports cars".

Unlike other convertibles, the rapid roadster’s performance statistics remain virtually identical to that of its donor car. Powered by the same (front mid-mounted) supercharged 5.5-litre AMG V8, which delivers 460kW and peak torque of 780Nm at 3250rpm, the newest SLR offers a claimed top speed of 332km/h (just 2km/h slower than the coupe).

Mated to an AMG Speedshift R five-speed automatic transmission, it bolts from standstill to 100km/h in the same eventful 3.8 seconds as the coupe.

Presumably, like the coupe, the two-seater convertible also blasts to 200km/h (at which Benz says conversation is still possible, thanks to "favourable aeroacoustics") in just 10.6 seconds, and takes just 28.8 seconds to reach 300km/h.

As such, thanks to its retracting roof, Benz says the second SLR model offers "undiluted open-air driving pleasure in the highest performance class", with the same everyday practicality and refinement as the coupe.

It features the same styling cues as the four-year-old coupe, including an arrow-shaped front-end that mimics the latest Vodafone-McLaren-Mercedes "Silver Arrow", front quarter louvers and side exhaust outlets positioned behind the front wheels, whose 18-inch diameter is dwarfed by today’s supercars.

Available in three colours and stowing cleanly away thanks to an integrated aluminium front front section, the folding roof opens and closes lightning-quick in less than 10 seconds. The only catch is that it’s not fully automatic, and requires unlatching and partial raising from the windscreen frame.

Reinforced steel A-pillars and two fixed rollover bars combine with the carbon body to provide passive crash protection, as do systems such as adaptive front airbags, knee airbags and side airbags, plus ESP stability control, seatbelt pre-tensioners and a tyre-pressure monitoring system.

For an asking price that’s expected to exceed the million-dollar sticker of the coupe, there’s standard semi-aniline leather-clad carbon-fibre bucket seats (with a choice of seat squabs to suit the customer), dual-zone climate-control, a premium BOSE CD sound system, multi-function sports steering wheel with paddle shifters and satellite-navigation.

Mercedes says the SLR Roadster is built using its strict quality-control systems. There’s no word yet on an even more ballistic Brabus-tuned version (to go with its 2005 coupe), which would probably lay claim to being the world’s wildest production roadster.