My GX460 is one week old. I am on my trial subscription with XM Radio. The regular radio works fine but XM keeps cutting out and it says unauthorized. If I turn off the engine and restart it, it will work again for a while and then cut out again. I called XM and they resent the authorization twice. It still does the same thing. As I live some 140 miles from my Lexus dealer, I was wondering if anyone else had a similar experience. That way, when I do get to my dealer, I can point them in the right direction. (I just know that the day I go to the dealer, it will be working just fine.)