Replacing a plastic rear window

The back-story. When I bought my Miata it had a Robbins glass window top. It was installed by the 2nd owner of the car (who I know) and I'm the 4th owner so the top had been on the car for a number of years. Last year I decided to install a roll bar. So I did my research and decided on a Hard Dog Sport double diagonal with modifications to work with a Robbins top. The roll bar installation proceeded without any problems until it came time to put the top down. It wouldn't go down, the glass hit the diagonals, preventing the top from going down! After contacting Robbins, I found out that early versions of the Robbins tops had a slightly different design and won't work with roll bars. So time for plan B.

My wife also has a Miata, hers had the original top with the original (now brownish) plastic window. So a couple of trips to the Crazy Red Italian and her car now has a Robbins glass windows top and mine has a the discolored plastic window.

Fast forward about 6 months and while trying to get the window zipped up, I crack the window (Hey, it's cold, the zipper isn't working too well, and the roll bar is positioned almost perfectly to block access to the zipper). The top is still in great shape, it's only the window that's in need of a little love.

Well, I really want a glass window, but I'm not willing to spend the money to put a new glass window in a 14 year old top and don't really want to spend the money on a new top right now. Search the Internet brings me to emiata.com. They sell a kit to replace just the plastic part of the window. You cut out the old one and glue in a new one. Easy and inexpensive.

A double diagonal roll bar makes the installation a bit more challenging. After thinking about it for while, here's what i did. It isn't perfect, but I do have a clear window that might be water tight.

Here's what the old window looks like. Lots of brown. The bottom was so brittle that parts of it crumbled off as I was cutting it out.
I took a piece of plywood about the right size and fit it behind the window opening. What you can't see in the picture is the stack of wood underneath the bottom edge used to prop it up.
It took a lot of test fitting and experimentation but once I thought I had everything lined up, I covered the plywood with wax paper. The instructions aren't clear if you should cut all the old plastic out or just the visible parts. I elected to cut all of it out since even some of the plastic that was bonded to the vinyl was cracked and crumbling.
Here's where I really deviated from the instructions. The instructions say to glue the window to the inside. And without the roll bar I guess it makes sense to lay the window down and do this. I didn't think that was going to work with the roll bar and I thought it would look better if it was on the outside like the original was. On retrospect, I think I should have followed the instructions.
To try and clamp it together I laid strips of wood over the window along the edges.
Here's my weight, half used boxes of coax and Ethernet cable.
Here's what it looks like after 24 hours. There are quite a few spots where it didn't seal or didn't seal very good. I'm now in the process of working my way around the window trying to seal it.