So I've had a 2004 C4S for a couple of years, and I've always wondered about a mod done by the previous owner. I was hoping the collective expertise here at RennTech might be able to shed some light on it.
There is a small switch of some kind on the carpeted side of the upper center console by the driver's right knee (two pictures attached). The switch is wired to a tiny speaker hidden in the A pillar trim to the left of the driver's head (pulled down from the trim in the attached picture). There are two moving parts on the switch. The center knob controls the volume o