My suggestion would be the Wittenberg control car because the "Kahrlsruher Kopf" from the Bremen-Oldenburg add-on can only be controlled with the BR110, which is where the Wittenberg control car comes into play because as far as I know it is compatible with almost every locomotive that has a push-pull control even with the BR218 which will be available soon. It would be a nice addition to the German fleet and the Intercity control car because in addition to the IC control car, the Wittenberg control car is also very popular and most Wanted with the German community as far as I know.
