My GN has an ASC roof and I have been slowly accumulating info. I believe that the were dealer installed. Mine has four drain hoses, one at each corner of the pan and the switch mounted in front of the glass. I recently bought a bunch of sunroof parts from a guy for an 87 GN and I got the ASC pamflet with a date on the envelope that read 1992 and a different glass manufacturers stamp on the glass than mine. It also has an automatic closing feature which mine doesn't have. Mine has only a small part of the headliner that appears to have been cut with a razor knife around the outside perimeter and stretched tight untill the tape for the wires let them drop and sag. Some I have seen pictures of have the switch on the dash. Someone posted something about cutting the ABS headliner for the roof. I need a headliner too. Wonder what the future value of a car with this add- on?