the surfliner has has 2 cars, a normal 2 level passenger wagon, and a combo wagon with the lower floor/level is baggage. the upper level is passenger and has a driving cab to drive backwards (push-pull). it goes on the end of the train. (many US commuter (small local passenger) trains are like that)
http://www.hebners.net/amtrak/amtCONTROL/amt6903.jpg
the same is true of the "cabbage". it is a locomotive with the engine removed, then they put a big door on it to use the space for baggage and still have a driving cab.
http://www.hebners.net/amtrak/amtF40CAB.html
Thanks for asking. if you want to put the question and answer in german for others feel free.
glad to see people are using the set. i have a lot of frieght stuff about to be released.