Humphrey said:
I narrowly escaped a 150eu fine crossing the border into France last month! The only reason the copper let me away with it was he loved the bus! Also I cable tied it to the front bumper while he was watching and promised to bolt it on at the next gas station. I'm running stainless steel bumpers though and my drill can't make a dent! I'm done the double sided tape job for now but I'm also looking into getting a smaller "custom" plate because the standard one just doesn't sit right.
Get a crafty sticker made,

On a chrome Bumper, it's a nice black and silver plate and almost legal, I've driven through 9 countries and done thousands of miles in europe and never had an issue.
I.e: