After spending months googling and ebaying for a complete replacement of just the rear zippered section, I decided that it was actually easier and cheaper to just cut and replace the plastic.
Long story short I went to a hardware store (Bunnings) bought a 2x2 metre (which was WAY too much)1.5mm thick plastic sheet, Tarzan's Grip general purpose glue x2, and a sheet of medium-grade sandpaper. Total cost approx $35.
You need a sharp and strong knife, pen/pencil, scissors, flat platform used to lie the zippered section ontop of, glad-wrap.
Not sure if this topic has been covered but here are the steps in general:
Whilst the soft-top is up and latched securely, and the rear section is fully zippered -
1) cut original plastic screen with sharp knife, preferably something with a bit of weight to it, and a strong blade. I used my MacGyver-inspired Swiss army knife. Cut around the whole screen in one cut (take it slow and steady) leaving a generous 5-10mm of plastic if you can.
2) use the plastic that you just cut as a template to mark the same shape on the new plastic. Lightly use a pencil or pen to trace around the plastic template with a 10mm or so wider margin.
3) Use preferably a large pair of scissors to cut around the outline
4) make sure to mark which is the top and bottom and which is inside and outside, then roughen up the inside border of the screen with sandpaper. Roughen the OUTSIDE part of the plastic screen, on the top, left over from the cut-out.
5) Unzip the rear softop section, lie it flat on the platform and use appropriate glue to stick the edges of the new plastic to the OUTSIDE edge of the softop together. Use glad-wrap to protect the platform from the glue.
I think you get the idea.
VERY IMPORTANT tip is to have a flat platform to lie the rear section flat. I used large piece of chip-board.
Not the prettiest of repairs, but for $35 and an hour of elbow grease, it's functional.
Hope this helps
