The BMW line at the Frankfurt Motor Show 2007 was that its new X6 Sports Activity Coupé is a “concept car”.

This has been challenged by some commentators who expect it in the showrooms next summer.

The X6 mixes X5 mechanicals with a snazzy coupé body. It will undoubtedly appeal to enthusiasts who appreciate its xDrive four-wheel drive system tuned for road performance. Also, all models will come with BMW’s “Dynamic Control Performance” active chassis.

The engine will be definitely sporty with two turbo-diesel sixes and turbo-charged six and V8 engines.

The consensus is that the X6 is rather unique. It has fine looks, and although climatologists might not like the idea of a SUV/coupé combination, BMW will counter by positioning it as a hybrid by 2009, claiming it will reduce fuel consumption by 20 percent.

It will be interesting to observe what emerges and when.

The C5 Airscape is a concept car from the old school. Citroen debuted its styling for the forthcoming C5 saloon at Frankfurt with this extraordinary show model.

Citroen C5 Airscape concept car

It’s said to be a fresh view on the world of executive cabriolets. If the next C5 emerges anything like as smart as the C5 Airscape, Citroen buyers are going to be queuing up for it.

It’s the front-end design that stands out. Bold new headlamps frame the chic double chevron Citroen-badged grilles, and the bonnet, with its neat feature lines, gives the C5 Airscape real sex appeal.

If this is a sign of Citroen’s future design direction, its rivals had better look to their mettle.

At the Frankfurt Motor Show 2007, a number of “cars of the future” are making a name for themselves.

Mitsubishi Concept-cX

The Mitsubishi Concept-cX is described as a “funky new proposal for a compact crossover with a ‘jet’ fighter” nose from the new Lancer. The raised ground clearance and chunky wheelarches are all its own, and despite the name, there may eventually be a showroom model of this car.

Crossover cars are very much in now. Nissan’s Qashqai is already selling well, Mazda has just launched the CX-7 and Ford’s Kuga is close to production, so people are used to the idea of a car that takes elements from both a regular family hatch and an SUV.

Bernie Ecclestone, owner of Formula One racing and a £3 billion ($6bn) fortune, is to sell 50 of his collection of exotic cars.

Mercedes-Benz 540K Special Roadster

He will he still own 100 old Grand Prix cars, however.

The cars include a Mercedes Roadster valued at £3.25 million and a £5,000 Ford Anglia that cost £660 in 1964. He has been collecting them since he started selling motorcycles and second-hand cars from a small business in Bexleyheath, Kent, in the 1950s.

The Mercedes-Benz 540K Special Roadster is one of the most important Mercedes-Benz of all time and the pinnacle of classic cars. It is expected to break all records for a Mercedes sold at a public auction.

The 76-year-old Ecclestone started out as a gas board worker before becoming a motorcycle salesman. He then setting up his own motorcycle and car sales business.

He even set up his own racing team at Brands Hatch, eventually negotiating the rights to show Formula One on television.

Experts say his collection is one of the most important in the world because of the rarity value of some of them.

A spokesman for RM Auctions, which is handling the sale of the cars at Battersea Park, London, in October, said, “The collection, built up over decades of careful acquisition, is composed of a variety of automobiles that represent many marques and eras. This auction marks what will be the first and only public exhibition of the Ecclestone Collection.”