BMW M3 CSL

The CSL strikes the perfect balance between raw entertainment and refinement. It's unlikely to be cheap, but buyers will get one of the finest drivers' cars around.

BMW is going back to its roots. To celebrate 30 glorious years of M cars, the German giant is, for once, taking a look in its rear view mirror. Not content with the performance of its standard M3 - which, let's face it, is hardly a slowcoach - BMW is about to unleash an even quicker version: the M3 CSL.

The brainchild of Gerhard Richter - visionary boss of BMW's M division - the CSL (which stands for coupe, sports and lightweight) has been designed to be the purest and most focused M3 of all-time. But why bother when the standard car has got a waiting list as long as your arm? Well, like many of us, the current 3-Series flagship is a touch wider around the hips these days. So, with its back-to-basics interior and lightened body, the CSL aims to put a little of the rawness and excitement back into M3 ownership.

Previewed at the Frankfurt Motor Show last September, the new model is still very much in development, something which the company is very keen to stress. The car you see here is one of only five prototypes in existence, and it's a rolling testbed for a range of exotic materials and electronics.

As a result, exact figures relating to engine power, performance and, crucially, weight haven't been released. However, what we can tell you is that the CSL is a truly outstanding development of an already fine motor car.

The first and most noticeable difference relates to its construction. The bumpers, doors, bonnet and even the roof panel are made from carbon fibre, which offers a significant weight saving - as much as 95kg, according to sources from within BMW - over the normal steel items. The same applies to the stripped-out interior, where the plush armchair seats of the standard model have made way for thin carbon fibre racing versions, while the main console is devoid of all but the most essential buttons and controls.

Under the bonnet, the alterations extend to a complete updating of the engine management system, a revised intake manifold and a general speeding up of the SMG gearbox's software. In terms of chassis modifications, the CSL sits lower on the ground and benefits from geometry changes designed to reduce understeer and improve front end turn-in. The 19-inch lightweight alloys cover 18-inch brakes and are clad in expensive-looking Michelin cut slicks.

On the road - or rather the damp twists and turns of our N�rburgring test route - the CSL sounds and feels like a born racer. The steering is hyper-accurate - lively, agile and faithful to even the smallest of movements - while the body control has been vastly improved and resists roll exceptionally well.

The transmission - an even quicker-shifting version of BMW's semi-automatic paddle change gearbox - is the perfect foil for the revised engine and hops its way through the ratios at speeds that would have been unthinkable even in a Formula One racer just a few years ago. But as with all great sports cars, the CSL has an edge to it. Accelerate too hard out of a corner and power swiftly overcomes grip, forcing you to correct or admit defeat and re-engage the DSL traction control system.

BMW freely admits that the CSL's final spec, price and production numbers are some way off - an indication that there's plenty of work to be done behind the scenes before the first cars are delivered. However, if Richter and his team manage to retain just a fraction of the prototype's raw appeal, we could be looking at the finest BMW for many a year. That's some prospect.