I went up and down this road with my 2005 4.4i. My truck had DSP, there is NO company that sells a plug an play unit that supports DSP. I installed the Dyanvin only to find this out when no audio played. Dynavin was no help. that began the quest, and up until I sold my X5 last week there was no aftermarket solution to this problem. I ended up settling for the MediaBridge which works good, not great.

I upgraded to a 2011 M sport X5 this week so I don't have to look anymore for a solution, but I would say Mediabridge is best option for you. Short of hacking up your car with crossovers and amps, it is the best way to go..