Brian,

I, too, have factory installed XM radio. The radio head is in the trunk near the battery, and the antenna is on the rear deck inside the car just to the passenger side of the brake light. The reception is good, but not as good as my 2005 4-runner aftermarket installation. I put the antenna on the roof directly above the rear view mirror. I also had a SkyFi II radio, and miss the scrolling sport scores and stock ticker. I have yet to figure out if the song/artist displays on the screen in the TCH. If anyone knows, please let me know.