This is the Citroen Metropolis, which as the name suggests is big enough to serve as Superman's second home. But unless you're reading from China, forget any plans to widen your driveway for now.

China has lots of money and an appetite for massive saloons. It also has a host of car makers whose brands aren't shackled by the fickle reality of European 'brand identity' - so it's perfectly ok for Citroen to make a massive luxury saloon and expect it to sell.

Roll on in the two-metre wide Metropolis, which is also longer than a long-wheelbase Audi A8 at 5.3 metres. Taking cues from the raft of outlandish concepts Citroen has recently unveiled, like the GTbyCitroen and Hypnos, the car was designed and developed in Shanghai. It sits on the same platform as the Citroen C6 saloon.

And of course the concept is a hybrid, of the plug-in sort. Its CO₂ emissions are remarkable given its size and claimed performance: 70g/km of CO₂ with 460bhp and 317lb.ft. Power comes from a 2.0-litre V6 petrol engine linked to a 70kW (95bhp) electric motor, sent to all four of the 21-inch wheels via a seven-speed, dual-clutch gearbox.

It can run in electric-only mode, though for how long and at what speed we have not been told.

The Metropolis's interior hasn't been unveiled yet, though China likes its limos luxurious; don't expect the tailpipe paucity to be matched in the cabin. We guess champagne flutes, Cohiba-spec ashtrays and more Swarovski than Donatella Versace's toilet roll holder.

The Shanghai World Fair motor show starts 1st May 2010.