Can anyone help, my 2005 CLK audio seems to go up and down and from surround (fronts and rears) to stereo (fronts) on its own occasionally. I have the standard Audio 20 and the Harman/Kardon speakers, I'm not sure if its caused by the radio locking on to stronger signals or radio broadcasts playing music at different bitrates, a loose wire or something else. Has anyone got any idea?
