Nice I just put my second single 12" in last night. Let me throw you some install tips that I discovered from my first install.
1. Read and heed that little tag that is attached to the box there. Those are the install instructions. When it says dont install with the grills mounted, it means it.
2. Put your woofers in and pre drill the mounting holes. The holes are going to be close to the cut out so angle the drill away from the woofer slightly. I used #8 1-3/4 screws and a 3/32 pilot drill bit.
3. I used the kicker grills from ******** for my 12" sub. They look good and have what looks to be plenty of room for xmax of your sub. You might want to check em out.
4. It is a tight fit putting it in place. I found that if you push or angle the driver side corner in first (as you are looking at it) the push the passenger side in, it makes it easier. When you get to that point it will make more sense.
5. When it is finally in all the way the top of the box is just touching the plastic molding pieces of the truck pass through, this is very true.
6. Finally if mounting your grills you need to loosly mount one screw to keep the woofer in place before you remove the other screws holding the woofer in place. Since the back is heavy from the motor/ magnet you run the risk of it tipping and stripping the mdf or making it a bitch to remount the woofer. Will make sense when you see it.
I didnt pay attention to the instruction and thought the box went all the way back top and bottom so I was smacking it with a heavy hammer, caused my woofer to pop out and strip my mounting holes. So I had to order a second enclosure.
Good luck and enjoy!
Cheers
K