The drip, drip of news about the new Mini MkII has become a torrent, with BMW unveiling the concept at Frankfurt – a barely disguised Mini Traveller.

You didn’t have to be Sherlock Holmes to pick up the clues; even Inspector Clouseau would have worked out that the next Mini would get bigger, more practical and that there would be more Minis available.

The standard three-door hatchback trundles into dealerships this time next year. This time, 1.4- and 1.6-litre petrol engines – co-developed with Peugeot-Citroën – provide the power, from 75bhp to 170bhp for the turbocharged Cooper S. PSA’s 1.6-litre diesel, with 90 and 110bhp, should also make an appearance.

The engines will pack out a front end that looks much like the concept’s, with that bigger, hexagonal grille and more steeply raked headlamps. This time they will be fixed to the body (which will delight service managers), but not behind a front-hinged clamshell.

Design chief Gert Hildebrand believes the runaway success of today’s car stems largely from sticking to the Mini’s iconic blueprint, and the MkII will be no different, evolving like the Porsche 911 has over 42 years.

‘We have a very clear vision about the Mini design language, proportions and graphics such as the floating roof, circular headlamps, short overhangs and muscular body,’ he says.

The next Mini will have more space inside. The new three-door expands by around 250mm longer to almost 3.9m-long, with much of that growth between the wheels to boost rear legroom.

The estate passes the 4m mark. Its rear seats fold flat to provide a 1400mm-long load bay. But the concept’s double-jointed doors won’t survive: ‘they are too expensive to be a production solution’. It won’t wear the Traveller or Countryman badge either, because BMW doesn’t own the rights. Sources expect Clubman to get the nod when sales begin in autumn 2007.

Another variant will follow in 2008 – the cabriolet. A two-seat speedster and fixed-head coupé are also on the drawing board.

Increased flexibility at the Oxford plant makes all these bodystyles possible. The changes are part of a £100m spruce up, which will also alleviate Oxford’s great bottleneck – the paint shop. As a result, annual production will jump by 20% to almost 230,000 in 2007, and could stretch beyond 300,000. So the MkII should reel in even more happy punters – and put a smile on dealers’ faces too.