Sirius Antenna Help Please (With Pics)

[PK8]

Just bought an '05 X5 for my wife. It came with BMW Sirius installed, which is working. However, when we bought the X5, I noticed the antenna was not secured to the roof (see pics below). While patiently (not) waiting for our Invision DVD system to arrive, I figured I'd tackle the antenna issue.

In looking at the bottom of the antenna (see 2nd pic below), it seems to me that a piece is missing, as there is no magnet as far as I can tell. There are a couple "bumps" on the bottom (under the white "cover"), which prevent the antenna from sitting flat on the roof. In addition, there is a long and thin magnetic strip attached (apparently, with double-sided tape) to the roof (see pic below).

Is the antenna complete? Is it missing a bottom cover w/magnet? Is that long/thin magnetic strip someone's attempt to fix the antenna install?

I am 75% sure that I will re-install the antenna in the spoiler (although I'm nervous that some have gotten poor reception doing so), but I want to make sure the antenna itself is complete/not missing something.

Thank you!

P.S. Sorry for the poor picture quality (cell phone).