From Siegfried:
Yesterday Anneli and I drove to Eisenach again to finally pick up the car. We got a brand new fuel pump through a very fast online car part dealer last week and it just took a few minutes for the mechanic in the garage in Eisenach to put the part in place (and to fix the break lights, which didn't work). After that the car worked just fine and we had no problems at all on the 350 km from Eisenach to Steinfurt.
The car runs just great (up to 140 km/h), but going high speed it becomes very very noisy! Good that on most parts of our trip to Mongolia, we will have to go slow anyway, since going fast might lead to severe ear damage!