just noticed that. awesome

 

me too... still very interesting but had to laugh when i read that

 

I know this is old, but after recently installing an XM Receiver Module in my car (my radio would say "XM Feature" when the 'CAT" button was pressed). There are at least 2 different shark fin antenna's ... one for the regular AM/FM/Onstar then the one I had to change mine from to the one with AM/FM/XM/Onstar. So while you may have a similar looking antenna, it may not have the XM antenna lead coming from it.

 

Actually the antenna is all in the shark fin antenna on the top of the car. I added an XM Receiver Module to my XM Ready head unit and had to change out the antenna as it didn't have the XM antenna wire coming from it, the antenna had a plug for AM/FM, a plug for the Onstar and (the new antenna) had a plug for the XM radio. I believe the one in the back may be an antenna for the RKE system (the key fob antenna) ... I do know that there's an antenna in the front windshield glass, not sure if it's the same for the back glass or not. But I do know that the radio antenna's are all in the shark fin on top.

 

The antenna that's plugged onto the upper left of the drivers side (sitting in the driver seat) is for the RKE (remote keyless entry) or the antenna for the key fob. There's a TSB about a replacement for the RCDLR as there's been issues with short range on the key fob working.

This is the link to the TSB: http://ww2.justanswer.com/uploads/Ch...d__2334176.pdf

 

Now if OP replied to THIS one I would be shocked.

Nice job concluding things tho. Too many topics go unfinished.