I picked up my new X5 yesterday and only had the Sirius Radio put in with the intent to install the Icelink which I had already purchased, however I can't figure out if the CD changer cables are used to hook up to the Sirius module or whether there are CD changer cables hidden back there also. I read on the Dension website there is a Sirius adaptor, do I need this and if so does a place like Best Buy sell it?