Personally, i think DAB is a dying platform
Internet streaming is the way ahead. Thousands of stations
I use DAB while at work but its patchy at best, stations not covered in certain areas
In my car i use the Tune in radio app bluetoothed to the iDrive, it get all same DAB stations and more
Mine is fitted with DAB but I gave up trying to use it. The damn thing cuts out every 10 secs and the screen displays "No Signal". Took it into the dealers and the service manager said "If you want to use DAB then park in your driveway in a position where you get a signal and then don't move". Save your money IMHO its next to useless.
Denison make a dab radio that will plug into the usb port in the arm rest.displays the stations as mp3 files. It can be hidden away but does need an arial on the windscreen. About £150