What you need, SD, is an omnidirectional DAB antenna on the roof, and a masthead preamplifier.
Keef, I don't disagree with that, and ultimately for the fixed unit that (or something like) it will be done.
But I can have a DAB portable sitting alongside an FM portable, and the latter just works, while the former just doesn't (at least, only partially, and with much fiddling).
That's why I agree so much with BEAGLE's post!
SD