Despite appearances, BMW’s relationship with the Mini brand is not quite as settled as it might be.

Although it clung onto Mini in the wake of the break-up of the Rover Group in 2000, there was a widespread fear within BMW that Mini could prove to be an expensive flop or a brief flash in the pan.

Read about and see the pictures of the 2011 Mini design concept here

Eight years on from launch, and after two generations of the new Mini family, that’s proved not to be the case. Even so, there are still plenty of worries about how BMW can grow the Mini brand so that it becomes self-sustaining.

Minis fundamental problem is that it is a relatively small operation (with sales of around 230,000 in a good year) using a stand-alone platform.

And it is not only BMW’s smallest volume platform, but the economies of scale are dwarfed by the BMW medium rear-drive platform which underpins about 800,000 new cars per year.

Even BMW’s big rear-drive platform (which underpins the 5-/7-series and X5/X6) accounts for sales of around 400,000 units per year.