http://www.visteon.com/products/automotive/satellite_radio.shtml according to their website the untis are made to handle either xm OR sirius satellite radio because they only make one unit. Ford just specifies sirius to them because that is who they chose to deal with. So it seems to me that one could have XM and install an 07 Shaker head unit with the satellite option into their 05 and install what ever is necessary to use XM and have a shaker design picking up XM and looking super clean. What do you think? I wanna do it.