A friend of mine said he figured out the XM hack.
Basically you have to sign up for XM. THey turn on your radio id,
you get the service. He said he let it run for 3 months or so, then cancelled. He said for the next 3-4 months of course his radio unit didnt work as they were transmitting the "kill" signal.
But he (having been a satellite haxor) hoped that XM couldnt afford bandwidth wise to transmit this "kill" signal from thereout for ever... he waited patiently, and a few months later they stopped transmitting the kill signal, and his unit started receiving the exact service he did before.
So for the avic's, I imagine it'd be good to sign up for the xm radio AND nav traffic, hang out, drop a couple dozen bucks, and if you are patient, see if it turns out to be a long term investment.
Personally, I'm not that patient!
z1, 6dvd changer, xmnav traffic w radio and traffic, tv tuner, aux input for a NON ipod mp3 device, 1500W system in a 2006 CRV with front and rear passenger video.