I have installed the XM Direct radio, with a Terk adapter for Toyota, in a 2006 IS with Nav. and AM/SAT button. Used advice from warhummer on how to get the dash apart and it cost $107 with tax. Dealer in southern Calif. wanted $999!! Works seemlessly, steering wheels controls work, it is really pretty easy. I can help, took many photos along the way. I cannot help with mounting of the antenna, I am using the child restraint location and it works fine. Let me know if I can help.