As I said, my styrene fab skills aren't fantastic, but in 1:10 the bits can be big enough for me to manage. In parallel with building the truck, there's also a conex ("shipping container", "ISO", etc). As drawn in CAD:
And then start to assemble:
Starts out as just 3mm styrene sheet from my local plastic shop, then 3D printed hinges, latches, and twist locks for the corners.
The latches actually work, if you're careful with them. The yellow splotch is a hinge for the handle; it's a piece of 3D print filament pushed through (1.75mm diameter), then melted on the end with a soldering iron to mushroom it in place.
Rather than actually corrugate the sides, I faked them with printed inserts glued into place. Rustoleum hides many sins.
Add some stickers, et voila.
This in turn fits onto a "flatrack":
to end up like this
As with the conex, the flat rack starts out life as styrene sheet, then has stuff added:
Most of the "stuff" is 3D printed, like the red A-frame on the left, but the tool box is left over from the body kit, and the tie downs on the sides are Fleabay Chinesium. They're so cheap that it's just not worth my time to try and print them, plus even the chintzy aluminum is stronger than printed plastic that small. The corners have snaps for the twistlocks on the conex:
They're so small I couldn't figure a way to actually make the lock twist, and in the end the thing weighs enough (just the conex empty is like six pounds!) that gravity holds it down just fine.
Like the 1:1, the back has rollers to facilitate loading and unloading. These are printed, and roll on a length of spring steel (aka a straightened paperclip. I've discovered that paperclips are amazingly useful in this hobby!)
The white blocks are added as I did some testing in the real world. My CAD design was nice and all, but keeping the flatrack aligned both fore-to-aft and left-to-right, while being able to load and unload it, turned out to be more of a challenge than I'd thought.
At the rear of the truck is a mechanism to not only roll the flatrack, but guide its frame rails on the angled rollers to keep it centered.
See highlight on the 1:1; not the same visually, but same idea functionally.