Bad Sirius Reception!!
I installed the same 9980 unit and Sirius radio and located the antenna on top of the center dash speaker under the grid (speaker is unpluged).
I got very poor reception.
I did not want to mount it on the roof for obvious reasons.
I did lots of web searches and reading and some seemed to suggest that having the magnetic antenna base on metal on some kind improves the reception.
My solution was to remove the center speaker and make a 1/2" deep basket out of a left over metal perforated speaker grill mesh. I made this very quickly by using a 3.5" hole saw in a piece of 2X6 wood.
I placed the piece of speaker grill over the hole and used the center piece of wood as a punch to pound the mesh approximately 1/2" deep into the hole, then pounded the edges flat to form a shallow cup.
I trimmed the flanged edge to the size of the speaker od and made a few snips for the hold down screws.
I installed the "basket" where the speaker used to be with the same screws and put both the GPS and the Sirius antenna in it.
I've had good reception ever since.
I'm not trying to explain why, just saying that it worked for me.
P.S.
I also had very poor FM radio reception compared to the stock radio even making sure the antenna was properly powered.
I installed a $7 antennal amplifier (from ebay) and now the reception is as good as the stock radio, not overly great, but just as good as stock

Hope this helps
Reposition your antenna to the top of your dash center against the windshield.
Hope this helps.
The installer and I drove all over town with me moving the antenna around inside of the car until we found the "sweet spot" for my car which proved to be at the base of the pssenger side "A" pillar. I pulled the "A" pillar trim off that side, mounted the antenna in the corner on top of the dash pad at the base of the windshield, then re-installed the "A" pillar trim. The antenna is completely hidden behind the trim piece, the trim piece fits just fine and my reception is good enough that it will even pick up all the Sirius stations while the car is in the garage. I hardly ever lose the signal (it only drops when blocked by a close tall building or close dense tree line and that is very infrequent). You might try a similar test with a family member or friend driving while you experiment with different locations inside your vehicle.
Last edited by vetteright; Jun 10, 2011 at 12:35 AM.
















