Not that I've seen yet. Any after market producers not partnered by EM would have to wait for an actual production Elio before they can finalize design and production.looking at your signature, I now recall the rear windows were to "wing" open. Anyone see it offered now?, i think it was one of the better add-ons
If the Elio has the rear windows glued-in it will be a little bit harder to install an after-market kit involving new glass. (or maybe drilling holes). I suppose hardware could be 'bonded' to the window but reliability might need assessment.
But if the windows are bracketed-in it could be an easy self-install. I'm thinking the hinges and latch are a good candidates for 3d printing. Giving the small producer a inexpensive entry into the mods-market.