Ok, I ended up chosing an aftermarket radio, an Onyx, bought online at walmart.com (yes, walmart lol) for $49.95.
I used two brackets from
www.proclipusa.com, total cost about $50, and mounted the radio on the console, lower, right hand side. I had an option to renew an old Sirius account laying around, so I used that to pay only $25.00 for six months service.
I wanted to use the Sharkfin, so I installed an extention from the radio to the OEM Sirius antenna plug in the trunk and it works great.
Here is the cable I ordered, 10' SMB Female Ell to SMB male straight, $14.95 with no shipping charge from Amazon: (If you can't find it, search for SBRGT-10.)
http://www.amazon.com/XM-Radio-Unive..._bxgy_e_text_b
Below is a picture of my install in the trunk. As others have said, the FAKRA antenna connector is pink, and in my car (2009 E92, M3) was in a buffer wrap neatly underneath the mounting lug next to the radio module. I literally just pulled out the pink FAKRA connector, and plugged the male end of the exention cable in, and it pressed home. The other female El went straight onto the male ANT jack on the back of my Sirius Onyx OEM radio.
(Picture shows cable unhidden)
Works great. I selected the amber motif on the Onyx, which matches the BMW amber in the instruments almost exactly.
Total cost just about $140 including the 6 month subscription. I'm pretty happy with that.
