found this video
The unit is controlled through the steering wheel buttons.
DAB Audio and Text station name sent over FM modulated signal to original head unit
humm would like a bit more information on that. Remember the FM Transmitters you could get for you're iPod, so that you could listen to the iPod on your car stereo without any wires? thats FM modulation - works great, when there is NO
That would be my concern with this