I use a milk crate to store spices, oil, popcorn, foil, pans, plates, and tongs. The lid of the crate is plywood and I use it to go under the butane stove or cutting board.
Separately, I have a cheap butane stove in a nylon bag (could use a wind screen tbh), a Dometic fridge, and a small garbage can. My tailgate is covered in marine plywood.
This is simple, effortless, and takes up very little space. It’s not super organized or anything but neither am I. I do dream about a pull-out setup but don’t like the space tradeoffs. The more I use the GFC, the more I want simple and reliable above all else.