This futuristic super-car, complete with Batmobile-style vertical doors, has been spotted on the streets of London.

The unique machine – which boasts the memorable “CEXI” numberplate - was parked outside a fashionable boutique on South Audley Street in Mayfair.

Although based on a Rolls-Royce design, the car is understood to be a one-off private commission.

DC Design, an Indian super-car firm, constructed it for a wealthy British-based client a few years ago.

Rolls-Royce confirmed that the car was not one of their own one-off creations.

“As a bespoke firm, there have been times when we’ve carried out coachbuild jobs, but nothing quite like this,” a spokesman said.

A new lap record has been set a Germany’s notoriously tough Nurburgring by a Cadillac CTS-V.

The new performance saloon from Cadillac completed a lap in just 7 minutes 59 seconds.

Cadillac claims this is the fastest ever lap set by a saloon car driving on standard road tyres.

The CTS-V is helped by a 6.2-litre V8 engine with 556bhp.

It has enough grunt to go from 0-60mph in just 3.9 seconds, making it faster than a BMW M5 or Audi RS6.

A six-speed automatic gearbox is standard for the Cadillac cars and it is likely to have a top speed limited to 155mph when it goes on sale in Europe in limited numbers at the start of 2009.

Cadillac’s general manager Jim Taylor said: “The V-Series takes the award-winning CTS sport saloon and elevates it to a position within the club of the world’s most exclusive and capable cars.”