Thanks everyone for your replies.

My husband called the ADAC office today and spoke to a nice English-speaking lady. She confirmed that we could get insurance for our car upon visiting their office in Frankfurt or Bremenhaven. We need the car title, driving licence and something she called "tax" (?sp) of the car. (DH could not figure out what it was, we'll call her again if I do not find the explanation somewhere.)

The rate she quoted is around 150 Euro per month. She confirmed that the insurance's valid in Switzerland.

It seems that the problem is solved. Again, thank you all for your input!

piglet