My solution to the cargo problem: trailer. Sure, there are plenty of trailers available for purchase, but they can be expensive and kind of dorky. Why buy what you can build? This just a simple wheeled platform fitted to carry my largest toolbox and maybe a little extra.
I started with a piece of electrical conduit, which I bent into a rectangle with rounded ends.
I did this with a simple conduit bender, available at most hardware stores. After the bending I just trimmed the extra piece and welded the ends together.
The frame fits the toolbox just right, so next I bent each end upward to make a cradle.
I did this with the conduit bender again, but since the sides are all connected I had to do each side incrementally, bending one side slightly end then the other slightly more. Once that was done I cut 1/4" bar into sections and welded then across the two sides. I will use bungee cords to secure the box while traveling.
The platform is now done and ready for wheels and a hitch.