Citroen has revealed that it plans to expand the new DS luxury brand with bespoke dealerships, exclusive membership clubs and new models – including new DS3 variants and three Chinese market-only cars.China will be key to the success of the DS brand due to its booming luxury car market and the high esteem European makers are held in there. It is currently Citroen’s second biggest market.Among the three China-only models is likely to be a version of the Metropolis concept, which could be badged DS9. The Metropolis debuted at the Shanghai Motor Show in May 2010 and was styled and developed by the PSA Group’s Shanghai design studio.It uses the C6 executive saloon’s platform and measures in at 5.3 metres – longer than an Audi A8 LWB.The Metropolis features a 2.0-litre petrol V6 engine mated to an electric motor, delivering 460bhp and CO2 emissions of 70g/km. Power is fed to all four wheels through a seven-speed dual-clutch gearbox.Bosses refused to reveal any further details on the Chinese models, but would not rule out a stretched version  of the DS5.More DS variants are bound for the UK, too. Following the launch of the DS5 early next year, Citroen plans to release more bodystyles and special editions of the popular DS3. A cabriolet version is believed to be among the models under development.The new variants will be sold under a revamped DS brand that will include a membership club – offering perks such as trips to Citroen-sponsored motorsport events – and big DS World showrooms in the largest capital cities.