Don't know for certain on the VW Dab, but I fitted a blaupunkt nashville DAB35 into my 55 plate GTI and also the same head unit into my wifes 08 plate ed30, and yes you do need a new aerial, if you get the blaupunkt dab bee sting aerial (which picks up both FM, AM and DAB) it is an oem swap with the std item and all the wiring you need is under the rear roof, no need to run new cables etc, just plug and play
blaupunkt is a great head unit and with a blaupunkt dab aerial the reception and sound quality is awesome, one of the best mods I have ever done to my car, kept the speakers std but the sound quality of radio has to be heard to be believed, better still the nashville allows you to record direct from the radio to an SD card, as an MP3, I have built up an awesome music collection from recording songs as I drive around the country
