[ford40]

Porsche does offer an auto dimming mirror...at least they did in 2004...assume they still do. I think there was a thread here about retro fitting one. The fine wire in the windscreen is the antenna...and I think it does double duty as the RF pick-up for the door locks. If memory serves the auto dim mirror wires run across the windscreen header and down the passenger side of the windscreen...I also had the impression that the wiring of this feature was not to terribly complex. But alas I'm an old guy and could be completely wrong on this.