Thanks to this 2020 thread...
http://forums.pelicanparts.com/porsche-911-technical-forum/1076181-911-sunroof-cancelled.html
...and my lifelong hatred for sunroofs, I had Perfect Lines delete it from Vents, my 1989 M491 project car car, in 2021.
I was looking for A) increased headroom (my head hits G Body Sunroof ceilings on bumpy roads), B) strategic weight loss (I pulled 22.5 pounds of sunroof components out of the car) and C) improved aesthetics.
This picture illustrates the headroom opportunity cost associated with nasty sunroofs...
~1.6 inches from bottom of sunroof cassette to bottom of outer roof skin (i.e. the ceiling)...
The process...
The results...
The full sunroof delete (parts, labor and primered roof section) cost $5,914 in 2021. I can only guess that it has gotten more costly during the intervening inflationary years.