You're absolutely correct, Steve. I remember reading that the sunroof alone is just over 12 lb. But add in the frame, motor, and additional structure and it could be more like the 25-30 lb range. Didn't Getty Design say their carbon roof was ~8 lb, and everything they removed was closer to 47 lb? So it may be ~39 lb max, but then add in the headliner, and the steel roof weighing a few more pounds than carbon fiber. Still, 30 lb weight reduction at the max height of the car should help drop the center of mass.

You mentioned that your car came with a new steel sunroofless top. Did it also have the headliner? I've been trying to keep an eye out for a good used black one out of a GT2 or GT3.
-Dan

 

I have not opened the large box that contains the roof, but my understanding is that I only have the new OEM roof skin and nothing else. I will need to source the headliner myself before undertaking the project.