To bring this thead back to life, crutchfield has the adapter now for the major brands that have xm head units for $49.00, and the brain for the xm is another $49.00, so its cheaper than even. My question for those that have them, is where you mounted your antenna, I found an alpine I like, but lately have been looking at locations. i want to upgrade to a better component set up front, and coax in the rear with an aimable tweeter for a good rear fill cause the stockers are busted and i wont pay for a component set back there, and a good 4 channel amp running one sub and the components.