I just had the same exact thing happen to me yesterday, drove with it like that, cause I had to go somewhere, it was giving me a headache thought I would have to call it in for service, but after being parked for ~ 1 hour, it was gone, I did disconnect my Ipod, not sure if that was the cause, because another time my radio was stuck, and would not come on or off, but that also went away. What's funny is that we have almost the exact same car, same color, sports package and ipod adapter.
I figured I'll just let them know when I bring it in for the free oil change, unless it happens again.
keep me updated if it happens to you again.
Happy holidays all !!!