First off I have a 2004 grand prix GTP with Comp G. I have the six disk changer and the satellite hook up. I just bought a pioneer AVH-P4100DVD double din deck and the GEX-p920xm unit to get satellite radio with the new unit. Now to the question, I want to know if it is possible to use the existing xm antenna that was on the car already to hook into the pioneer xm unit. does anyone know if it is possible to do? Any help would be appreciated!