I have a 04 Boxster (7000 miles) and have experienced several times that the radio system appears to be working, but there is no sound. I contacted the dealer who told me that sometimes the fibreoptic cabling to the unit could be wound to tight, and instructed me to lock the car with the remote, and unlock it again, and the problem should be fixed. It seemed to work, but what the heck is that all about? Is anyone else experiencing this problem?