This is another option to upgrade-Pioneer shallow mount sub in stock location.
Opening is almost a perfect fit-I had to grind it few tenths of mm-it is very snug and would stay in place even without screws. I still put couple in and siliconed the seam for air tightness.

I ran into snag with disassembly of rear deck-I couldn't figure out how to remove ski hole opening garnish, but there're hidden metal clips on top(green arrow). You really have to pull it up to disengage. I couldn't find reference to it in shop manual either-I have rear reclining seats.
Rear deck is held in place by pretty much nothing-there're 2 blue push clips(purple arrow). As soon as you take armrest/ski opening granish and rear quarter interior panels(big plastic triangles between the door and rear window) it comes off very easy.

I put Fatmat everywhere I could stick a finger, including under the seat, on trunk floor, on side plastic panels and inside spare tire well. Pictures are just at the beginning-I covered almost everything, multiple layers around sub(from trunk side as well).
Seat belt assemblies are particularly rattle prone-I fired a sub before putting everything back together in order to trace rattles. There's not much you can do-rattle comes from inside of belt assembly and I strongly advise against messing with those parts. I siliconed black plastic buckets in which assemblies reside to the rear deck, stuffed foam to the sides of seat belt mechanism(make sure it soed not interfere with seat belt operation!) and layered extra fatmat around it. With rear deck in place and music cranked I didn't hear anything rattling.

Please take extra caution taking side quarter panels out-they seem to be crack prone. Try to stuck your hand behind it and push and pull at the same time. I didn't crack mine, but there's too much flex there.
I am totally happy with SQ. This is subjective thing and for type of music I listen to I do not need even need a sub-front components(MQ Quarts) provide excellent tight punch. My complant would be poor midrange, but that is a topic for different upgrade.

Amp installation was covered quite a few times, nothing new is here. I ran patch cables in the middle and installed it inside spare wheel. 100% stealth and full use of trunk space, no visible wires anywhere.

 

Thanks for the write-up.

I think I'm going to be taking my rear deck apart again, as I've got some little ticking-rattle thing that sounds like something's tapping the rear window that I want gone. If I do, I'll probably do up pictures of the rear pillar trim, which is very prone to breaking clips.

 

+1 thanks for write up,
I just did mine, but sub isnt working and I wasnt able to take pics, I will mat mine this weekend, and try to finish it up,


What size are you using for a spare?
What is the black stuff on the sides? to raise the rest of the trunk to be flush with the bigger tire?
do you keep the tool kit holder thing over the amp/tire?

 

It is stock 17" spare. This black stuff came with the car-I am not sure if some cars came with temp spare tire. I also do not have tool kit holder
But I do not keep anything on top of the amp to avoid overheating.