Ok, so I have the basic system in my 2000 c230, and I am adding a parrot CK3100 bluetooth system in it, I will not connect the car speakers directly, I cant find a harness, so I am going to add an external speaker and mounted under the the driver dash. but for me to be able to do that i have to find out how to mute the radio when a call comes in. so my question is, which wire is the mute line going in the stereo. if i can find that out i can tap into it and the system would work, i did it on a BMW before, but for this one i cant find the mute line.