Thread: Adding Sirrus XM to 2008 Grand Prix

Hello, I recently picked up a Grand Prix that does not have Sirrus XM or On star. I was able to find a GM Sirrus XM add on kit for 2006-08, this includes the Sirrus receiver, antenna, and wiring harness. The problem that I have is the Sirrus antenna is supposed to replace the original On star antenna but since I don't have On star, there is no antenna to replace. I can drill a hole in the roof and attach the new Sirrus antenna and wire, but I'm not sure if the Sirrus will work without the On star. Anyone know if On star is needed in order to get the Sirrus to work, or is it a completely separate system with nothing in On star needed to work the Sirrus.
Thanks
Dave

If there is no solution for your car, I'd like to buy your equipment. I have a satellite antenna and an XM module. I just need the rest of the bits to make it happen. If yours does work out, I need to know how you bought all the bits.