I have the base head unit in my 2007 C230 and installed an aftermarket setup this weekend. Have the speaker outs from the head unit running to a Fosgate 360, which feeds separate sub and 4 channel amps. The Fosgate is set up to send the remote power on/off signal to the Infinity amps, which works fine. When I turn off the head unit while the ignition key is in the 'ON' position there is no issue. But when I turn the igntion off while the head unit and amps are on I get a very loud pop.
My guess is that I need to find another power source? After install it occurred to me that tapping the wire that keeps the head unit temporarily on after the key is in off mode might have been the way to go.
Any suggestions appreciated.