My next imagineering project - lexan rally door windows for a cab

[widebody911]

Well, it's time to put some windows in this thing. I ordered flush-mount rear and quarter window kits from TRE MotorSports, but I have to fab the door windows myself.

My 'vision' is for 935-style, aka 'rally' windows, and I could just pick up the phone, call TRE again and order a set... if I had a coupe. However, the coupe and targa/cab window profiles are different, so I have to make my own. My fiberglass doors can't accept normal window frames, so I'm going for the VW bug "one piece window" look.

So far I've built a template out of hardboard, and I've rigged a mounting system. The mounting will consist of an aluminum channel inside the door, like a stationary version of a window lift, and matching channels on the sides. I may use pieces of aluminum angle on either side of the window at the level of the door, depending on how stiff this arrangement turns out to be.

I'm using at least 3/16" Lexan (polycarbonate) but I'm thinking of bumping up to 1/4" to get a little extra stiffness.

The next bit I need to engineer is the actual opening. What I'm trying to figure out is how large I can make the opening without compromising the material too much.

So what's the point of this post? I'm looking for feedback, helpful hints in working with Lexan, caveats, design suggests, etc.