BMW's next generation Mini will be built from a more flexible platform which will support four or five different body styles, according to Mini UK general manager Trevor Houghton-Berry.

Design studies for a two-seater coupe cabriolet had been considered while the current cabriolet was under development, he said.

Mini's worldwide commercial success over the last three years, had opened up "a host of exciting possibilities" for the future, said Houghton-Berry. These could include an estate built on a stretched wheelbase.

For this year, the cabriolet is virtually sold out. The Birmingham motor show had generated "an explosion of interest" and the UK's allocation of 6,500 was accounted for with the exception of a few hundred cars when the cabriolet goes on sale on June 26.

With the Oxford plant, a one-time Rover large car facility, already working three shifts, seven days a week, a decision was imminent on whether to increase capacity beyond 180,000 a year. "As ever the paint shop is the bottleneck and Munich is studying a number of possible solutions," said Houghton-Berry.

The plant was designed to build 125,000 cars a year but demand from 73 markets had far exceeded expectation.

The UK is still the number one market, with 40,500 annual sales. The USA is next with around 35,000 and Houghton-Berry said he expected the USA to overtake the UK in the next couple of years.

But there were some concerns raised by the success of the Mini with demand constantly exceeding supply. "Customers will wait two to three months, but would they wait six to seven months?" he asked.

Current waiting time for the Cooper derivative, which accounts for 50% of sales was three to four months, while Cooper S customers have to wait five to six months.

Full year convertible sales are expected to be around 8,500 in the UK, he said.

Houghton-Berry said he was pushing for a greater degree of showroom separation in the 152 UK BMW dealers where the Mini is sold. "It makes sense to share backroom functions and infrastructure so we won't see any stand-alone showrooms but the dealers are doing so well that they don't need much encouragement to move Mini out of the corner."

He said that he saw little overlap between the Mini and the forthcoming BMW 1 series. The Mini is bringing a new, younger type of buyer into BMW dealers which gave the dealers more opportunities.

 - While BMW plans to redesign its 'retro' Mini, Volkswagen this week ruled out redesigning the new Beetle, according to reports.