Fiberglass doors

[Modern_manBr]

I still think that if you want a light door you should get rid of the stock glass and window regulator, (the regulator itself and the glass weight almost the same as the rest of the door)
I fyou still plan to use the roll up glass, use a pice of lexan with clear windows film (the same used for tint has a clear version, used just to make a temperd glass "work" almost like a laminated glass when it breaks).
but the better idea woul still be a carbon door (fiber glass at least) with thin lexan bolted (I hate pop rivets) to it, you can make a slidding window for the driver side and keep the passenger side as is (why should you care for the cooling for your passenger? If your passenger is a girl she would probably even enter a VW bug anyway)
on my car, my plans are for running lexan the same thickness of the stock glass all around (excep the windshield), with the stock rubber and even the stock trim (my car will look as much as sctock as possible)