You also need to factor in where the aerial(s) are going to be fitted. That DAS unit has inputs for four of them!
For just DAB (integrated with CIC), Mobridge are bringing out a unit (
http://www.cartronics.co.uk/media/pd...-DAB-Flyer.pdf) and Dension do an add-on unit for their Gateway 500S product (
http://www.dension.com/dab-solutions)
Regarding aerials, the problem in my E91 is that I would need to replace one and maybe both of my rear side windows to retrofit the OEM aerials.