This is based on the "DIY Drawer less Drawer System for SUV from single sheet of Ply Wood for overlanding and camping" from All-Terrain Family. Just custom fit to my 5th gen and then adding two additional fwd platforms to create a large flat sleep platform.

Upsides:
Cheap
Can store stuff above and below without needing to dig through stuff / move it around (ie cooler on top with access, while gear can be pulled from underneath without disturbing one another)
Flat!
Strong and very stable
No 'moving' parts (bearings / latches)
Quick to remove and replace (less than 5 minutes to install and uninstall two forward platforms [40/60 split]).

Downside:
Labor (cut/assemble/sand/waterseal/adhesive non-slip/adhesive carpet)
Rigid (need a good pad otherwise it's like concrete for my old bones)

Basic Build Tools:
Drill
Bits
Screws
Circular Saw
Sander

Basic Build Hardware:
Angle Aluminum (for slide-out)
Two 4x8 3/4" plywood (Rear only = 1 sheet, two forwards = 1 sheet)
1x1 scrap wood for lip retention
Carpet
Adhesive
Drawer-Non-Slip (under carpet for minimal cushiness)
D-Rings
Felt for sliding
Stain/waterseal
Turnbuckles
Wood glue

Full Platform with Slide-Out (shown not slid out):


Rear Platform with Slide-Out Tray and Two Front Platforms Stored:


Retention of fwd platform to aft (small overhang lip. Note that the aft vertical leg over the plastic seat hinge and is sanded down to not rest directly on the plastic):


Both fwd platforms installed:


The bottom rear seat cushions can be quickly removed (4 bolts) for an additional ~6 inches of room.

Attached Images

               

looks good. Are you planning on adding the pull-out drawers?

No plans for pull-out drawers. There is a built in table/shelf that slides out at the back. I can get away with boxes, like the front runner wolf pack or something similar. That gives me more flexibility to move boxes around a campsite instead of loading and unloading drawers.

Looks great. Can the front part of the platform be flipped up to so you can put the seats up easily?

Looks awesome! Lower drawers would be killer.

The front parts can be pulled up, and then slid under the rear platform for storage and flip the seats up. Less than 3 minutes to do that.

Thanks, might have to give that a try. Looking for some sort of setup for the summer.

I like this a lot, I might build this as a lock box/ platform. Tired of getting my car broken into/ need a platform.

what carpet did you use? do like it? does it have integrated padding?

really cool!

Carpeting is "Absolute C20BK 20-Feet Long/4-Feet Wide Black Carpet for Speaker Sub Box Carpet rv Truck Car Trunk Laner" from amazon (used maybe half, probably less). There is a thin layer of 'padding', which is just non-slip drawer storage liner. 3M sprayed adhesive. Basically same concept as in the DIY video.

We are doing a similar build taking inspiration from a bunch of storage + platform builds. I find it easier to design on a computer so I created a 3D model of the trunk of a 4runner 2015 trail edition. I used a free online tool called SketchUp. Same one I used to design my fiancee's engagement ring!

It has all the exact measurements. I plan to post our design later, but we've gotten the base built off of the 3D design and so far everything fits like a glove!

Hope this helps some other people when designing their own build!

https://app.connect.trimble.com/tc/a...Pur399Km29nnlA

Do you still have the measurements?

Looks good!