This wasn't strictly required for good bass, but I wanted to do it, so I did.

http://imgur.com/a/UgePv

To gain access:

1. Remove the 5 covers on the cargo door sill
2. Remove the 5 philips screws holding it down
3. Using a trim tool lift it up - 5 clips plus 1 on each end.
4. Remove the 2 covers on the rear passenger step (that helps you get into the 3rd row)
5. Remove the 2 10mm bolts holding the rear step in place
6. Using a trim tool, lift the rear passenger door sill
7. Remove the 2 14mm bolts holding the 3rd row seatbelt and the rear passenger seatbelt in place
8. Remove the 2 10mm bolts holding the right side cargo tie-downs in place
9. Lift the cargo carpet (it slides under the right cargo panel
10. Remove the 2 phillips screws holding the right cargo panel to the floor
11. Pull the right cargo panel away from the wall. Straight towards the center of the vehicle, not up. You will need a trim tool to pry the panel away from the catches on the 3rd row seat pivot
12. Before pulling too far, unclip the connector from the 115VAC plug
13. Open the cargo area window vent
14. Pull the cloth liner partially away from the wall. It's mostly clips, but there is a hook holding it on above the blower motor. You just need enough clearance to remove the subwoofer
15. Unclip the subwoofer connector
16. Remove the 4 10mm bolts holding the subwoofer in place. Wiggle the top off it's hooks and remove it from under the cloth liner

I also wanted to check the blower for cleanliness, as there isn't a filter on it. Turns out it was in great shape. The air flows through the grille on the cargo panel, down to the floor, then behind the blower housing before entering the center of the blower. So there's plenty of places for dust & dirt to drop out before it can clog the expansion unit.

To gain access:

1. Lift the covers on the plastic top of the 3rd row seat pivots (look for the white line that indicates the "hinge")
2. Unbolt the 2 14mm bolts and remove the pivot
3. Unclip the wiring harness on the top-left from the blower body. You can get behind it and push the clip to one side with a stubby screwdriver and pivot it out of the oval hole. No need to cut it or release the zip-tie.
4. Using either a flat-blade screwdriver, a hex driver, or a Torx driver (I used a flat-bade) remove the 3 screws holding the blower in place.

To re-assemble, the order is the reverse. The seatbelt and 3rd row seat pivot 14mm bolts should be quite tight, as you don't want them coming loose in an accident. The 10mm bolts can just be moderately tight (don't strip them).

Chip H.

 

Good idea. I was hoping to replace the stock subwoofer with something that has an extra punch. I went to West Coast Audio and she claim the rear was an 8 inch sub so I left. haha. I was hoping someone came up with a stealth box or fabricated something.

 

There just isn't room in there for an 8" driver and the needed airspace behind it (even if you use polyfill stuffing in the box).
The existing driver looks like a long-throw 6". The enclosure is sealed (no port).

Go ahead and buy that wedge and strap it down in the cargo area.

Chip H.

 

I really wish we had the 8" potential the 4runners have.. I've kinda been debating a small down firing sub if I ever replace my factory system so I can stack junk on top of it lol