Now go look in your trunk. left rear side by the tail light. pull the carpet back. should be a 12 pin harness that hooks to absolutely nothing. black connector IIRC. if that's there your car is at least XM ready. Those NAV units are XM ready whether or not the receiver is actually in the trunk. if the harness is there...get an XM box and antenna and plug it in and bam. XM. - Though any USED XM unit will display "XM Theftlocked" - they only learn a vin ONCE and that's IT. it can be hacked by yourself or cleared by a specific company. see: http://forums.corvetteforum.com/c6-c...-resolved.html or http://www.gpona.com/forums/04-08-gr...lf-t21816.html - a list of compatible XM modules should be found here : http://www.grandprixforums.net/satel...dio-37036.html
That aside...based in the picture...the USA Spec adapter i posted should work for your application. Otherwise there is the ipod Lockpick which should also work.
GM IPOD LOCKPICK
that device also allows an AUX input as well and can be installed with or without XM.