Lamborghini is marking its fortieth anniversary by unveiling a roadster version of the Murciélago supercar at the Detroit Motor Show.

The Lamborghini concept Barchetta was designed by Luc Donckerwolke, the head of Lamborghini Design, and has a more aggressive design compared with the Murciélago, from which it was derived.

Sources say the car was inspired by the open racing cars of the ‘50s that used to race the Targa Florio or Carrera Panamericana and follows in the footsteps of the 350 GTS, Miura Roadster and Diablo open-top.

The Barchetta has streamlined headrests that are integrated with the car’s air intakes and the asymmetrical leather cladding - the right hand side being in a different colour and material compared with the left hand side. Lamborghini claims the asymmetrical trim enhances the driver oriented cockpit!

Under the skin, the car is similar to the 6,2-litre V12 four-wheel drive Murciélago that created a stir at the Auto Africa Show in October last year.

But because the roof has been discarded, structural parts of the chassis have been re-designed to ensure an adequate torsional stiffness. The ride height has also been lowered by 13,6 mm.

Producing 427 kW at 7 500 r/min, the Barchetta’s powerplant develops 650 N.m of torque from 5 400 r/min. In a full-throttle charge through the six-speed ‘box, the car is capable of sprinting from zero to 100 km/h in a staggering 3,8 seconds.

Four-pot calipers have been specially developed for the car's set-up, which is further enhanced by drilled and vented brake discs.

As is the case with the Murciélago, the Barchetta has 18-inch alloy wheels shod with massive 335-section tyres at the rear.

”Driver aids are plentiful: traction control is to be standard, along with a four-channel ABS, complete with electronic brake-force distribution,” a Lamborghini spokesman said.

"At higher speeds, pop-out air intakes are complemented by a height-adjusting rear wing that reduces lift on the rear axle, improving maximum-speed stability," he added.