on the topic of split windows, perhaps the split doesn't have to be at the center.
the citroen c3 picasso has an interesting setup
while this is pretty new in the front many cars mainly hatchbacks and fastbacks, have something similar at the rear, so perhaps existing side and windows could be used. some 80's and 90's cars might have some thing in the back that would be perfect flipped around. the ford probe comes to mind but i think some toyotas might have this too... rear windows could be a problem due to the defrosting wires but perhaps they won't block vision that much, and would give you a heated front windshield! but otherwise i think combining rear side windows with a portion of a front windshield could give you the shape you want using cheap, replacable and possibly law complient parts