I have an Alpine headunit with a Sirius hookup in my 2001 Passat. The factory "whip" antenna has seen better days and is due for replacement. I am looking to use a New OEM "sharkfin" antenna from either a VW or Audi (both cars can be equiped with Sirius) with one of those antennas.

Two things I am concerned with:

-Splicing the Sharkfin into the Sirius reciever.
-Making sure the FM part of the antenna still works.

Thoughts, comments, suggestions?