Like some other GX owners (and the original post), I was interested to recover some of the height and remove the weight of third row seating (that I could not imagine ever using)....
I like the Goose Gear solution, but didn't want to spend the money - and wanted the satisfaction of doing it myself (with talented son). I also want the flexibility to remove the platform and modify it as I learn more about how I use the truck. Driver's side will have oversized spare tire storage initially, and would be location for fridge enclosure mid-term.
There are a number of great resources, I referenced the work of Pachari Adventures on youtube for removal (he does a good job of sharing bolt size and showing locations) and then de Winj family (Australia) "Getting Liam's Boot Ready" 28 Feb 18 for install <
Getting Liam’s boot ready >
Removal went pretty easy. The seat assemblies pretty heavy for being so compact.
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For platform assembly, I bought 3/4 inch ACX plywood (sanded one side). Like the Liam build, I used one rectangular piece and used ribs underneath. I used three ribs (instead of four like Liam) : one just inside the rubber seal (3/4 ply in one inch strip), second across the four visible bolts (2x2 with cut outs), and third on carpet beyond the ridge (3/4 ply plus 1/2 ply). I took some time with a random orbit sander to get this smooth(er) and reduce chance of splinters when handling. At this point, four 2.5inch bolt in the second rib hold the deck in place.
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Next steps will be to install the wooden vertical sides (probably with L brackets in a routered channel). Found some 5mm rubber exercise equipment matting at home depot that will likely go on top. I also have recessed L-track from US Cargo Control on order (and will router a channel for that).
If of interest to anyone, I can post more pictures once the rubber matting and L-channel are installed.