Hardtop Duster?

The curvature would be the big deal. The mechanisms and hardware would be a piece of cake compared to the custom glass you'd need to roll them up and down. The Duster pop out glass is too small to make a roll up window out of because it has a gasket on the bottom side too, not to mention the "pillar". You'd need a piece of glass with the same shape on the top, but then continuing straight down from the "point" of the quarter glass.

My guess is that you'd have to use Lexan if you wanted it to be even slightly cost effective.