Transferring the cardboard template over to some MDF bracing board that was 5mm-3/16" thick. I choose this thickness as was the same as the stock glass that was in there. Can also see the 1/2" I added extra to the bottom. Also made sure the front and back edges were square to each other. The best place to centre the guide rail of the electric window system is at the balance point. This would be the middle if top and bottom, plus both sides were parallel to each other, but not the case with one piece windows. So I found the point by balancing it over a round pencil and marked the spot. Primitive but effective.
No trimming was needed and fitted first go. The balance point of the template was marked from top to bottom so I could workout where the the electric window needed to be fitted. No binding as it went down either. I could also mark the door where the balance line was at different points. It must remain exactly parallel to the window channels on each side though.
To know what the distance from the mount to the glass needed to be, I measured from inside the panel to the side of the template close to where the bolts would go. Did the same for the bottom mount. This is flipped around to show how much needs to be trimmed off the top to fit inside the door and have the mount on the ridge. Balance point line on the template tells me where to mount the guide rail left to right inside the door. I had it lined up exactly in the middle of the left and right glass clamps.
The ruler inside the clamps for the glass gives me where to measure too from the inside panel to the glass. It measured 38mm and I only needed 32mm. So I flatted the mounting bracket enough to loose the 6mm extra. The two mounting bolts are now holding it in place. I made sure the guide rail was parallel to the window channel to stop any binding. Also put a straight edge across the template to make sure it stayed flat as it went up and down to check the mounting position was right depth wise. Our American Akita doing a photo bomb!
The bottom mount had to be flatten some as well as wanted it to sit back a bit from the panel face. You can make out the bolt I will use also to support the motor itself. A simple bracket with a little joggle in it secures the bottom of the guide rail. Made up a Z bracket for the motor to keep it supported and off the door skins. Could have also bolted with a spacer directly through the inner panel, but didn't want the thick bolt head to stick out.