What is the best way to install a third-party sattelite radio antenna on the roof of a 2007 TL? I'm addicted to Sirius and not XM (must have my NFL Network). Is there a way to either snake the cable into the cabin unobtrusively (or maybe mount it on the trunk?), or somehow tie into the existing roof antenna?

Thanks for the advice......

 

Arent they merging? you might be able to get both soon...

 

Not worth the trouble. You can add an antenna to the corner of the front windshield. There is an old thread with a member converting the XM antenna to use as a Sirius antenna.

As leedogg stated, it might not be worth it in the long run: It's Official! XM And Sirius Are Merging - MERGED THREAD

edit:
Found some good threads for you: