In 1934, the German Army began the process of creating a series of standard military passenger vehicles (Einheits-Personenwagen). Each vehicle type was to have all-wheel drive, a locking differential, a standard chassis, and interchangeable components.

The plan was to build a set of three weight classes by different manufacturers, but according to similar general specifications. The companies of Horch, Wanderer, and Opel were to be responsible for producing the medium vehicle, which was designated the Mittlerer Geländegängiger Einheits-Personenwagen Typ mPI (Kfz 15).

The Kfz 15 was of conventional layout and was powered by a 68hp 3.6 liter water-cooled engine. Opel produced roughly 10,000 of the 35,000 medium military chassis that were built between 1937 and 1943.

The Kfz 15 on display is on loan from Dr.med. H. Didjurgeit, and is one of the earlier models that had two side-mounted spare tires to assist in rough terrain. Later models carried a single spare tire mounted internally.