Is this plate legal?

In Germany you get in trouble, when you make changes on plates, even on the blue Euro-bar on the left. It's a forgery of a document, because valid (with the silver county sticker seal on) plates are documents here.

Most common is, to put a little round sticker of football clubs in the Euro wreath of stars.
And there are Nazis, who cover the Euro bar with black-white-red stickers.