Your neighbor, that has German residency, will need auto insurance on the vehicle if he plans to drive it in the US, which it sounds like he will do when going to the port. Typically, most insurance companies will only insure a vehicle to someone with a foreign or international license for 30 days while the person is working on obtaining a license from a US state.

Your neighbor would be helped if he started finding a shipping company that will export the vehicle from the US and import it into Germany. This company might be able to help him find an insurance company that will cover his vehicle while in the US and during the time of it being shipped over to Germany. Shipmyvehicle.com is one site that gives information on shipping vehicles and what is needed for the process.

What will be required of your German neighbor for exporting from the US can be found at cbp.gov, the US Customs and Border Patrol site. As for the what is needed in Germany he will need to contact the German government to find out details of what all documentation and inspections will be needed to get the car properly registered once the vehicle arrives there.

If your neighbor gets a US license to drive his vehicle in the US for awhile he can get a fast, free automobile insurance quote here.