Where do you get those little circle stickers that usually go after the first 2 letters?
A German MOT station and Insurance company for an authentic one.

I'd be surprised if you can get them legitamately because if I remember rightly they are a visual MOT and Insurance display or something (like that

) so that the rozzers can see whos driving without insurance and MOT and drivers have to update and change the stickers every year, a pretty good idea if you ask me.