After the war, there was a major lack of luggage wagons for highspeed long-distance trains. However, the young DB decided to use the available money to construct new passenger carriages and to solve the luggage wagon problem through conversions. In order to do so, it used approximately 600 substitute passenger carriages that remained in its inventory. Passengers could not be expected to travel in these wagons due to their interior fittings and their mediocre running properties. Two of these car bodies were connected, equipped with a strut bracing and placed on two American-design bogies. The approximately 290 luggage wagons that were produced in this manner from 1950 onwards were given the MPw4ie-54/55 and MPw4yg-57 designations. Although the first wagons were only equipped with the open entrance platforms from their donor carriages, they were quickly replaced with a transfer tunnel in order to offer a transfer to the next wagon whilst also being protected against the elements. This transfer was also then equipped with a rubber bulge in order to connect to modern wagons. DB arranged for numerous medical and auxiliary equipment cars to be built using the same construction principles. To begin with, the wagons were first used in the premium high-speed train service. However, they were then moved to express goods and district services upon the emergence of new wagons. Some wagons were given additional equipment for the transport of freshly-hatched chicks and travelled in express trains between Italy and Germany. Numerous wagons that were given the designations MDyg-986 and -996 from 1966 onwards were further modernised and equipped with panel walls and new rubber-mounted windows. These wagons also remained in use in this design after 1989 and were also used in the DR (German Railway) area for the transport of express goods. The use of these wagons was halted suddenly in 1992 following a tragic train accident. A buffer fell from a track maintenance wagon causing 14 goods wagons to derail with which an approaching express train collided. The cause was material fatigue on the console upon which the buffers were fastened in order to create space for the access platform. Consequently, all wagons equipped with such consoles were removed from service and only those that had to be used were refurbished. This affected the auxiliary equipment cars built on the same principle but did not affect the MDyg.