Yes real german word but there were many made up ones for the fun of it, usually on t-shirts.
Farfrumpukn, fukngrvn, and such
When I had an isuzu I had a plate the said GOFARTHR. Actually I still have it.
I got a german plate on the front of my Jetta that says Vorshict. Basic translation "Watch out"
got it from here.
www.germanplates.com