If it's in the dock, it needs an external antenna, and unfortunately without the dock you can't use the FM modulator (if you wish to go that route).
The easiest solution would have been to just put the Helix in the sunglass tray and use the FM modulator, but that would have only worked with firmware 1.05.
I used to have the ipod and an OEM Sirius solution in my other car (pre-335i). I realized I just didn't listen to the ipod as much as the satellite radio. Plus, the Helix allows for MP3's, so I'm just more careful with which songs I have in there since I'm limited in storage.
If I could control the helix with my i-drive, i'd be in heaven....