got the amp at my local ovation. Here are some pics:
Boston GT-40

First, I cut the carpet. Then I mounted a scrap piece of ABS plastic (I get it here at Purdue pretty cheap from Meyer's Plastics) into the floor. I then siliconed the screws from the bottom side (very important to do). Then I mounted the GT40 to the ABS. It has adjustable feet which REALLY helped when I mounted it. It's driving my VR600s right now, but next free weekend I get my XR650s are going in the front doors and the VR600s will get custom mounted in the back doors. The seat has FULL travel w/o hitting the amp and with the seat all the way forward, you can access the setting/connections of the amp which is really nice. Plenty of power and clean sound, it's a nice little amp for under a seat.

NEXT UP....

- begin my custom fiberglass enclosure to hold my JL 10W3v2 sub

- install my JL XR650s in the front doors

- put the JL VR600s in the rear doors (this will be a fun project)

Special Thanks to Eclipse20 for his input/experience with this exact same setup.

Cookin' with gas now.....

Nice work. I have installed everything BUT the amps. Sub amp under the passenger seat, and 4 channel under driver seat. Will finish tuesday. I will also post pics of my custom fiberglass encloure I made. Probably won't help you though as my X is a an 05.

Again nice work!

Looks good, but couldn't you mount the amp without cutting away at the carpet?

I don't have my 05 X yet so I'm not sure what it looks like underneath, but I've done amp installations on other Nissans. What I did was pull up the carpet from the side and shoved a piece of MDF (1/4") underneath. Put the carpet back down and then screwed the amp on top. I used the air ducts underneath and routed the wires through there.

Again, the X's may be different, but when I sold my car, I pulled my stereo out and the new owner never knew anything was there.