The issue relates to the acoustics of the car, not the equipment. Instead of mounting the microphone on the drivers side A pillar, I fed the wire up thru the dash and mounted it below the dash hood over the instrument cluster. I then reduced the volume of the speakers to about 80% and only ran sound out of the drivers side speaker and viola! no more echo complaints from the other person. At 80% volume the echo is practically non-existent, as you increase the volume the echo gets progessively worse. The location under the dash hood basically isolates the microphone from most of the sound wa