So I read the California vehicle code, and I guess this is something that they never thought of....
There are rules for the size, shape, and reflectorization of plates, but no rule that says you cannot fabricate your own plates. I suppose you could get cited for not reporting a lost plate to the DMV, but there isn't any language to cover a situation such as using an exact replica of a plate...(disclaimer: read the code yourself, I make no warranty as to my interpretation of the CA vehicle code).
BTW the code says nothing about having to mount your plate right side up...
