Car change time again, this time I'm considering a BMW. The BMW 520d SE to be precise. I'd like the Logic7 option, but I also want MP3 & DAB. What's the best strategy here? How integrated can aftermarket fitted systems be with the I-Drive? Is there a specific DAB & MP3 audio system as an option on the 5 Series? I'm a little hesitant to go to my local dealer as I'm intending to buy using one of the many discount services. Most options are straight forward, but the audio is a little confusing. Thanks, Mark.