These are 2 trailers I made years ago, but never finished because I didn't have the materials to finish them. I recently dug them up again, and maybe I'll finish them still... I'm still trying to decide.
This is the first one: made to be pulled around by my Pajero. The intention was that I could drive my mini on there without any help.
I made these trailers by straightening copper wire used for electrical leads in walls and such. I cut off the desired lengths and soldered them together. In the beginning, this is real easy. But when you start having a lot of copper and a lot of soldered points, it gets harder: the copper conducts the heat very well, and the other points tend to melt loose again.
I made the bottom bit of the ramp with a slightly different orientation of the bars: this way the mini would keep its grip when driving onto the ramp.
This is how I attached the wheels: old uprights from my minis with a copper wire through there. I improved this system in the second trailer.
The mini on top. Too bad my mini was not assembled when I took these pics, but you get the picture.
The second trailer, behind an unfinished Pajero-shell (with finished chassis, ofcourse). This one has four wheels, and was much more complicated to create (aligning the wheels etc). At first I wanted to make it a flatbed trailer, but I decided to make it a closed one. Well, it's supposed to be 'closed' when it's finished. Now it looks rather open ;)
This trailer is completely symmetrical, where the previous one wasn't. The first one was constructed to hold together. This one was constructed to hold together while looking good. Apart from 2 details (which I couldn't fix because I ran out of wire), it should be perfectly symmetrical.
The slightly improved wheel-system. Because I had only steering uprights left, I had to drill holes and make sure the uprights stayed in the right place.