Sorry for the
So far I'm concluding the E82 roof construction is equal regardless of sunroof option:
1 The RealOEM bodywork roof diagram show, except for the roof sheet itself, the exact same parts used for the 1M and other E82s (with or without sunroof option, S403A=Yes)
2 Glassoman's statement:
Originally Posted by Glassoman55
As far as I know, the roof should be exactly the same as and 135 or 128....technically you could install a roof with the sunroof cut out on a 1m ...
3 Images in above thread that show the default E82/ 1M roof construction has no crossbars underneath the sunroof area.
Having a decent body shop retrofit the OEM sunroof sheet would not be much of an enterprise, price tag excepted.