There is a school of thought which says you can tell an awful lot about a man by the way he chooses to wear his hair, and Adrian van Hooydonk gives credence to it.

Day and night his locks are studiously floppy, with the occasional bouncy flick for those moments when he wants to emphasise his unconventional motives or complement his wry humour. It takes a lot of planning and effort to get his fringe to fall just right across his forehead.

It is a triumph of creative determination; a minor conquest of nature. It tells us - in other words - that in the pursuit of the unconventional and avant garde, he is willing to do whatever it takes to 'make it'.

Van Hooydonk has just made it - becoming chief car designer at the most avant garde car firm in the world: BMW. For the past four years the Munich firm has delighted in shocking its admirers with the most radical, modernist cars any luxury car company has dared produce.

No-one had heard of 'flame surfacing' or the 'Bangle boot' in 2000 - but, thanks to BMW's newly promoted creative design director, Chris Bangle, they are today as much part of the automotive vocabulary as A, B and C pillars.

Now that the most controversial car designer of his generation has been kicked upstairs to take overall control of BMW's new babies, Mini and Rolls-Royce, as well as BMW itself, what everyone inside and outside BMW wants to know is what's next?

Will Bangle's successor opt for a quiet life? Will Adrian van Hooydonk pause for breath and wait another generation before turning out radical new models?

The man with the toughest choice in car design agreed to talk exclusively to Top Gear in his new Munich design studio. Van Hooydonk admits BMW has made mistakes - the first generation iDrive cabin control system was "not right, right away" - but he passionately defends BMW's design revolution.

He dismisses press critics as blinkered, says the market was more intelligent than the media, accuses rivals Mercedes and Audi of copying the Munich marque, and promises even more avant garde design to come.