2008 300 Signature Series - Radio is playing. Then all of a sudden, after about 30 seconds, screen goes black, music plays additional 30 seconds although volumn knob/On Off button do not work. Then music stops. About 30 seconds later, "Chrysler" appears on screen, then Accept button and music starts again for about 30 seconds, then screen goes black, music continues 30 seconds then goes off and scenario starts all over and over and over. Any suggestions?