Thanks for the input. I have found very little info on that receiver p/n other than it was stated as a replacement part in a TSB for complaints of FM fade so it appears that it is a legitemate part but not sure of its features. There is one for sale locally and is included with an entire MK4 set-up but the person selling cannot verify if it is Sirius compatible. I am looking to upgrade my MK3 so that I can have sirius and share DVD maps with my M3.