I would like to see the pictures of the install. Which RTL do you have? Do you have Navi? I believe there is an available 14 pin connector on the headunit. I have the RTL with moonroof and XM built in the HU. On one of the front buttons, there is a button that reads CD/Aux. Does that mean pushing the CD/Aux once will activate the CD changer and pushing it again will activate the Aux function...whatever that may be. I know that Honda is coming out with an MP3 player that connects to a 14 pin bus on the HU. My thought is to use an Auxiliary converter using the 14 pin bus. Check out these links:
Link 1 ,
Link 2 and
Link 3 . Any thoughts on any of these products? Is this the way you plan on connecting your XM unit?