I have the exact same noise coming from my 2002 C320. It started this past weekend and each time the car starts, the harsh clicking noise engages, sometimes it stops, sometimes it doesn't. When it doesn't, I have to turn off the car and restart it. Did you ever bring your car in to have issue corrected. Does anybody know what this could be. I'm guessing a blower motor, or maybe the servo that engages the automatic steering column. Any tech's car to weigh in. What else is hidden under the dash? Almost sounds like it's right under it to the left of the center grill for the vent/center speaker???