BMW has unveiled plans to produce a stunning new coupe with an all-aluminium body and a top speed of 125mph.

The BMW X coupe concept car is based on the four-wheel-drive chassis of the X5 and has a three-litre turbo diesel engine with state-of-the-art common rail direct injection and developing 184 bhp.

The X coupe's power plant has been modified to produce 332 lb-ft. of torque. Stability at speed is enhanced by a rear spoiler beneath the bodywork. Normally flush with the vehicle's bottom rear edge, the spoiler extends downward automatically at 68 mph to generate aerodynamic downforce.

A five-speed Steptronic automatic transmission takes its power to all four wheels and the driver can control the gearshift via "paddles" on the steering wheel with the gearbox in Steptronic mode. Massive 20-inch wheels carry 225/50 tyres at the front and 285/45 at the rear, adding emphasis to the coupe's assertive presence. Run-flat tyres make a spare wheel and tyre unnecessary.

BMW says the X coupe is less of a 2+2-seater, more of a 1+3 because the vehicle has been uncompromisingly orientated towards the driver.

Controls only of interest to the driver can be seen only by the driver. For example, the engine temperature and fuel read-outs are located in the driver's door.

A low-mounted lever on the centre console gives the driver access to the colour monitor of the multi-function control system. When pressed, this lever changes the shape of the dash to reveal the monitor and control panel beneath. This control system was first shown in the Z9 concept cars and controls the entertainment system, cabin comfort, navigation and telematics. For the X coupe it has been further refined to allow GPS navigation functions to operate off the road as well as on.

New lighting technology contributes to the X coupe's active safety. The headlights, for example, steer with the wheels for effective illumination of road curves. Input from the GPS navigation system allows the headlights to anticipate curves ahead and to illuminate them properly.