In 1908 and 1911, several different express trains were built for the 1/2. Class, 1 ./2/3. Class and 3. Class as well as packing cars for the growing long-distance traffic ordered by the guide and MAN by the Bavarian state railway.

The 4-axle express train carriages of the Royal Bavarian State Railways sailed in Epochs I to IV. They were in action from country railway time to DRG (Group Administration Bayern) to DB time. In the beginning, they were used for express trains in the interior of Würzburg, Nuremberg, Lindau, or Regensburg, but also on long-distance trains to Berlin, Frankfurt or Stuttgart.

At the time of the country railway and in the early days of the Reichsbahn period, this type of car also ran in the FD 79/80 Munich-Berlin-Munich long-distance train. The FD 79/80 was equipped with up to four AB4üBay08 and one to two packaged cars Pw4üBay09. In other long-distance trains, ABC4üBay11 and later C4üBay11 were also discontinued.

These three types of cars had 3.5m rotary frames of the Bavarian design and an iron frame on which a sheets of wood was placed. The interior of the AB4üBay08 consisted, for example, of the AB4üBay08 B. from two 1st class compartments with eight seats and five 2nd class compartments with 27 seats as well as two toilet compartments at the end of the car. Length over buffer was 19 725 mm, the car box was 18 425 mm long and the rotary tap distance was 13 200 mm.

The country carriages were equipped with gas light. They could be braked with both suction air and compressed air. In the Reichsbahn period, the gas lighting was replaced by electric lighting, so that the gas canister under the car was removed and replaced with batteries and switchbox. Other rebuilding measures that have been carried out include removing the emergency stepping boards and ladders, as well as redesigning the WCs. The elaborate painting with ornamental stripes has also been replaced by a simple oxide-green paint.