Done
Back in Black by
Tyler Linner, on Flickr
Thinking the cargo tray, though perforated, could be replaced with some solid 2" thick styrene insulation sheet. The weight would be a fraction of the fiberboard and probably about as strong.
Tip: always drill a pilot hole when using a forstner bit. I muscled through it but it is uncomfortable and quite honestly unsafe.
Wool blanket came out; it's not winter anymore. About a pound. Took some stuff inside that I don't need while driving around. 3lbs.
I've got a good 5 lbs in the emergency kit in the tire well but that's going to stay. It's got tire goo, jack, tow strap, jumper cables, crescent wrenches, a bright safety vest and more.
Busted out the windshield sun shade too.