Numberplate for trailers

I needed a numberplate for my bicycle trailer. In Germany these car attached devices only have to show the numberplate of the carrying car. This is an attempt to make an improved version of my cardboard-felt-tip-pen solution.
I am currently printing the first one of four parts. The letters and numbers are slightly recessed into the base plate and should help gluing the whole thing together. I will add a photo once I have finished. Depending of the maximum size the printer can do, I edit the OpenSCAD script and comment out the fragments not currently needed.