An update on the Sirius install.......
I did the installation myself last night and it only took me about an hour to complete, including the activation. The installation was sooooo easy! I really think anybody with half a brain could do it.
I decided not to mount the antenna on the exterior of the car because I wasn't too crazy about having an antenna mounted on my trunklid. Yep, BMW recommends that the antenna (which is a round, flat, black and about the size of a flattened golf ball) be installed right in the center of the trunklid!!
I read somewhere on this board that others have installed the antenna on the inside, so I decided to give it a shot and mounted my antenna on the rear deck instead. It's barely noticible there and in my opinion its a much better way to install the antenna.
As for the quality of the reception with the antenna mounted on the inside, I drove around all night and I only lost the signal once and that was because I went under an overpass.
I'll try to post some pictures of the antenna mounted on the rear deck when I get a chance.