Spyshots Mercedes 300SL Gullwing

As Porsche prepares its luxury Panamera, and Aston Martin worries over its four-door Rapide, Mercedes-Benz is certain of success with its upcoming Gullwing.

It knows the combination of the retro-futuristic Gullwing name and body, and a 320km/h mechanical package from its go-faster AMG division, will mean certain success for the fastest car to carry its badge.

The Gullwing has been an open secret for more than a year, with camouflaged test cars running around Europe and logging laps at the Nurburgring, but now company executives are talking openly about the car.

Benz's safety chief, Ulrich Mellinghoff, talks now about crashing testing carbon fibre body parts for the Gullwing and the head of AMG, Volker Mornhinweg, is dropping hints about the engine for the car.

"The crashing testing is more like a convertible. There is no energy path through the roof," says Mellinghoff.

He also admits the nature of carbon fibre, expected to used for the majority of the car, means there will be aluminium crash panels at each end to absorb impact forces.

"With carbon fibre you cannot see if there is any internal damage. It can look perfect, but crumbles if you bump it."

The biggest question of all for the Gullwing is the engine, with Mornhinweg talking enthusiastically about everything from a new V6 - which is being developed for the baby A and B-Class cars - to the existing 6.2-litre V8 and the V12 used in the SL 'Black Series' with twin turbochargers.

But his biggest hint is that something new - perhaps a new-age 5.5- litre V8 - could do the job.

"We are working hard on something we launch in 2010. It will be a new engine," he says.

"I think later this year we will have more to say."

But he lays false trails everywhere, talking about a range of powerplants.

"We work very hard on our current 6.2-litre engine. There are a lot of new technologies," he says.

"Direct injection with piezo control . . . to make combustion in a perfect way. We also have some opportunity to put the turbocharger on some engines.

"For the smaller cars we have decided on an engine, but I don't want to talk. It's a very interesting thing, we have outstanding performance but we can reduce the fuel consumption."

Getting away from the mechanics and safety, the Gullwing is expected to have a paddle-shift gear system, LED running lights in the top of the headlamp cluster and giant metallic disc brakes.

It is intended to completely out-strip the McLaren-Mercedes SLR, a joint venture between Benz and its Formula One partner which has never hit its original sales targets, including production of as many as 6000 cars a year with a price-tag in the $500,000 range.

The Gullwing is widely predicted to star for Mercedes at the Frankfurt Motor Show later this year, although its debut could be pushed back to Geneva in 2011 if the company decides its is inappropriate to make a huge splash during the worldwide economic downturn.