I was way off on my guess of what this is supposed to mean, I was on the wrong track, and was thinking it has something to do with BMW, like a name of a German city. Nope.

 lol, well, I went with the BMW thing, and maybe was reading too much into the BMW colors on the plate, and Nürburgring, with the BNG at the end of the plate, and HM B G could be Hamburg... and then I was stuck thinking about German city names

Turns out, it was all California granola instead, because for unknown reasons, this beemer owner wants you to know they are a human being.