McMerc SLR blows its top

The Mercedes-Benz SLR McLaren has already established its rightful place at the pointy end of the supercar pecking order, and now comes a drop-top version to put the wind up the likes of the Lamborghini Murcielago Roadster.

As per its coupe sibling, the open-topped McMerc SLR is propelled by an AMG-fettled supercharged V8 engine that belts out 460kW and an earth-rotating 780Nm, and these outputs mean it can leap to 100km/h in 3.8sec and achieve a top whack of 332km/h.

Importantly, Mercedes claims driver and passenger can still converse at 200km/h with the top down without resorting to yelling, thanks to "favourable aeroacoustics".

In keeping with the McLaren-Mercedes Formula One heritage, the SLR Roadster is constructed from lightweight carbon-fibre, which is claimed to endow it with the same torsional stiffness as the coupe version -- so scuttle shake shouldn't be an issue.

Another benefit of its carbon-fibre-intensive construction are "exemplary energy absorption", resulting in "extremely high occupant safety", according to Mercedes, which also boasts of  "ride characteristics of the kind otherwise found only in closed-top super sports cars".

Mercedes says the newcomer (due on sale internationally in September) rekindles the spirit of the successful SLR racing models from the 1950s via its distinctive lateral louvers and side pipes behind the front wheels.

There's also clear visual links with the current McLaren-Mercedes F1 cars, thanks its arrow-shaped snout.

The fully retractable soft-top hasn't compromised the stunning lines of the SLR, and it (the top) is offered in a choice of three colours. The roof opens and closes semi-automatically in less than 10 seconds, which is up there with the quickest of drop-tops.

To open, the roof needs to be unlocked from the windscreen frame and be briefly raised, after which it folds away electrically. Mercedes says the aluminium cover integrated into the roof's front section "elegantly closes off the top when retracted".

Ample tuning in the wind tunnel means the SLR Roadster is as aerodynamically efficient as its coupe sibling, according to Merc, and it features an airbrake integrated into the access lid and a rear diffuser to provide increased downforce.

Stopping power comes from high-performance carbon-ceramic brake discs (but those who have driven the SLR coupe complain of a non-progressive brake pedal).

Standard safety kit includes adaptive airbags, knee and side airbags as well as seatbelt tensioners and a tyre-pressure monitoring system.

Also standard are a high-quality BOSE premium sound system, multifunction sport steering wheel with gear-change paddles, navigation system with integral radio and CD player, and semi-aniline-leather-upholstered carbon-fibre bucket seats, which can be individually adapted to the driver and front passenger via differently sized seat pads.

But you can put that cheque book away because the SLR Roadster isn't Oz-bound. There's always the possibility of importing one privately, though…