I ordered the same stuff that you did and after removing the paper backing, cutting the holes for the seat mounts, I then attached a piece of Reflectix to the top to go up behind the roll cage and around the rear window at the bottom. I used the Peel and Seal flashing tape used for roofing to adhere the two materials together and then proceeded to cover the rest of the black foam material with the peel and seal tape. It took a bit of pressing to really get everything to adhere together properly, because it's 100% humidity here. I'm gonna let it sit in there a few days to meld together and then I still need to cut two more slits to allow the rear window Velcro straps to wrap around the lower part of the roll cage bar.
I also found it was much easier to set in the bottom part 1st, then put the Reflectix in through the top between the roll cage and rear panel and lower it down to meet the bottom piece. After removing the paper backing on the bottom piece I then over lapped the two materials by about 4-6. Then covered the seam with peel and seal, of which I had enough to go back over to cover as much of the exposed black foam. Finally I dropped a piece of plywood behind the Reflectix and between the rear window and used a razor knife to slice out an area to still access the window. Everywhere except the upper portion against the window is really thick and should repel water and block the noise and heat well. In theory anyways...actually it does seem to reduce the noise quite a bit.
