Originally Posted by apw2607

Wow .. I'm just reading through now.

Your radio is good.
Your Board monitor is good.

The only thing left to try is the NAV MK IV. According to Martin at BMWNAV, he suggests that the Firmware inside the MK IV has to be 3.0 or higher for Sirius to function correctly. Perhaps thats the problem. After all, you've changed pretty much everything else !

http://www.bimmernav.com/BMW_Sirius_..._Retrofit.html

65.90-6 920 182 SW1.2
65.90-6 920 713 SW2.0 (and SW3.0 ?)
65.90-6 942 908 SW2.0 & SW2.1
65.90-6 942 910 SW ?
65.90-6 942 908-03 SW3.0
65.90-6 951 629-01 SW4.0
65-90-6-971-353-01 SW5.0

http://www.bimmerboard.com/forums/posts/168922/

Good Luck !