I don’t know if I ever talked about the need in Germany to register, but it’s quite serious business around here. If you are only staying for a few days in a hotel, than there is no need to do anything as you are automatically registred– but if you are staying for more than 4 days – even with friends – as I understand it you are supposed to register with the local authorities. If you move to Germany you have to register within the first three months, and if you move from region to region within Germany you have to de-register in one place, and re-register in the latter location. I’ve even seen locals worried because they did not register a house guest who was staying a week. After all that, I can’t tell if it’s the government or me who is paranoid. Based upon the looks of this car, I’d stand in line to make sure they know you are there.