Contributor SunnyUK dug out this interesting press release suggesting this integrated DAB unit is a commercially available product called AutoDAB from Connect2.
http://www.getdigitalradio.com/dab-news/view/374
While advertised as £299 fully fitted by BMW dealers, it is available online from Halfords for £149 plus £30 for fitting in select Halford Centres. This takes one hour
http://www.halfords.com/webapp/wcs/s...Id_265865#tab1
This is for an AutoDAB unit with vehicle specific wiring harness with required connector for the I drive as well.
Customer review is positive: good quality sound and operation, seamless integration, use through existing steering controls and voice prompt, but the window patch antenna on passenger side not invisible.
http://www.halfords.com/webapp/wcs/s...Id_265865#tab3
I specked my F20 with DAB and thoroughly recommend it. But if you are a radio/music enthusiast and miss it, or have a HK/hifi upgrade, you may wish to consider this.