In the years following the great war, Bruno realized how much of a target he had painted on his back ,and that of his family. While his enemies in more prestigious positions of power were largely deterred from making an attempt on their lives as a result of what the man had done to Belgrade in 1914.
Insurgents, political radicals, and just lone wolf threats had far less to lose. And Bruno needed to make sure that he and his family were well protected during transit. He had long since fortified his home to a high level.
But transportation was another matter, and had invested heavily into armored vehicles, such as limousines and trains, that provided his family military grade protection, while looking like civilian assets.
His private train, for example, looked like one of the modern diesel powered high-speed trains that were coming online across the German Reich, and the Russian Empire. as the 1920s roared like a tidal wave.