Originally Posted by SapphireTorrent
Yeah, that antenna is for the OnStar System only. If you go to Pontiac.com and look at the upper right side you'll see a link called "Owner'* Center." If you click on it and register one of the benefits is you can access an Adobe PDF version of your owner'* manual. Although I did get one when I bought my car, I find it much easier to just open the PDF file for quick reference while on the computer.
Absolutely go the pdf route, much easier than thumbing throught the book.
Anyway, I not so sure about the OnStar antenna being the one on the rear glass. I found this while researching another problem I'm dealing with:
Diversity Antenna System
Your AM-FM antennas are located in the front
windshield and rear window. Be sure that the inside
surfaces of the front windshield and rear window are not
scratched and that the lines on the glass are not
damaged. If the inside surfaces are damaged, they could
interfere with radio reception.