Do you have a write up on the sub install? I'm not looking to buy your jeep, but that looks like a great job and I'm tired of my box jumping around everywhere.
I first had a box up against the rear seat but it was a pain in the ass when I folded the seats down to haul things and found this to be a good fix for that..
Step 1:
Build a sub box to the dimensions of 30" X 14" X 8" (Do not mount in the sub until the box is mounted to the rear swing door)
Step 2:
Remove the inside plastic cover on the swing door.
Step 3:
Remove all of the bolts from the outside of the rear swing door.
Step 4:
Open up your rear window to allow for holding the sub box in place while drilling from the outside with the rear door closed.
Step 5:
Place the sub box into place against the door with the door closed on top of a 1/4" to 1/2" board or spacer so that it lifts up the box a bit so that it will easily clear any mats in the back when mounted. (Remember DO NOT block the door vents.)
Step 6:
I found it is much much easier to just simply drill out the existing bolt holes in the outside of the swing door as opposed to using threaded bolts (makes life MUCH easier, trust me!).
Using a corresponding drill bit to the width of the bolts you use for mounting drill out all the factory bolt holes continuing on through the rear of the sub box.
Step 7:
Use rubber seal washers and extended bolts (about 2.5' to 3") bolts to continue through the door and into the rear of the sub box.
Note: Make sure when mounting you the breathe vents on the driver's side of the swing door unblocked for when you roll with the front windows open as to not blow out the back window with pressure.
Step 8:
Once the bolts are pushed through you can then install the nuts on the inside of the sub box through the hole for the subwoofer in the front of the box.
Step 9:
Attach your wire on your sub on the inside of the box and install your sub and optional grill cover (much recommended).
Step 10:
Enjoy!

Never done a write up before so take it easy on me.. I just have spent a shit ton of time busting knuckles and learning from mistakes. Let me know if you have any other questions!