Several guys on here have done this Parisa and I'm sure the MSCCD have very good first hand knowledge they can give you, I know quite a few members of the group on Facebook.
https://www.facebook.com/MSCCD.DE/?ref=br_rsI could give them or your friends contact details via a pm if you or he are not members of the German Club if it would help.
http://www.msccd.de/One TM member has just done the same to NZ having had 6 months touring UK with no fixed UK address, it wasn't cheap but it worked through Headley Insurance Brokers + ask to speak to Chris Watts.
https://www.headleyinsurance.co.uk/special_schemes/morgan_sports_cars/From an insurance perspective I think they are worried that you may be a Zigeuner
.
