Mercedes-Benz prepares to take the wraps off its most advanced SL Roadster yet. We know that’s what all automakers say but this all-new SL is made almost entirely of aluminium. Taking its SL (for “sporty” and “lightweight”) nomenclature rather literally when compared to its predecessor, the new SL’s aluminium shell is 110kg lighter. This contributes to an overall weight that is lower by as much as 140kg. The car, to be assembled at the automaker’s Bremen facility, is the first Merc with an almost-all-aluminium bodyshell (89%) in series production. Some (well, a few) components are made from even lighter materials, including magnesium, and high-strength tubing in, for example, the A pillars. TRANSFORMER: The all-new SL Roadster testing in Dubai. 'HEAVY PASSENGER'Dr Thomas Rudlaff, responsible for the SL’s shell, said: "The effect is rather as if a heavyweight passenger had got out of the car and taken his heavy flight luggage, too."The result (of the weight loss) is perceptible and measurable. Less weight means more dynamism and lower fuel consumption."As a bonus, the aluminium structure is also stiffer than the previous SL’s steel construction, which has brought about greater passenger safety and les vibration.Mercedes’ flagship droptop also debuts a number of top-end features such as the FrontBass audio and "magic vision control" windscreen washer systems.BY END 2011FrontBass uses the free spaces in the aluminium structures in front of the footwell as resonance spaces for the bass speakers; the vision control delivers washer fluid directly to the wiper blade, taking the direction of the wipe into consideration, so a blast of water can’t be seen from the cabin. It includes a mode for cabriolet driving, which spells the end soapy suds in your eyes while driving with the top down.That’s nifty. Merc has promised to reveal the new SL “before the year is out” so we’ll definitely expect more details before 2012 swings around.