We just got a 2007 Acadia without factory installed XM. I've read pretty much every post re: XM. I've noticed that there are Terk kits that will allow you to use the factory installed stereo with XM. However, these kits include a tuner amongst other items. I'm wondering if anybody has been able to find a harness that allows a MyFi to act as the tuner that connects directly to the stereo (ie: connects Myfi direct to stereo, and use stereo as interface). This way, you could hide the MyFi in the storage box on the dash while driving using the stereo, but still have the portable unit. Any help would be appreciated.