This started as an intermittant problem, The speakers seemed to stop playing sounds. It has now become constant. If you turn on the car but do not start the engine there is a slight hum and if the volume is put on full you can just hear the radio (changing the volume does not affect the volume of this hum) If you start the engine the hum becomes quite a loud whine (don't think its alternator whine though, doesnt change with acceleration) Has anyone else had this problem? I have checked fuses and tried to run diagnostics. To no avail. can anyone help?