Steyr ADGZ Heavy Armoured Car. Originally built in Austria for the Bundesheer (Austrian Army), they were integrated into the Reich’s equipment, like the rest of Austria’s weapons and vehicles.

Some were given to the Reichspolizei, which used them for normal policing purposes. Most were given to the Waffen SS, which in the early years of the war were barred from ordering weapons to German industries (all products were to be used by the Wehrmacht); the Waffen SS had to make do with captured equipment, mostly Austrian and Czechoslovakian.

The Waffen SS were satisfied with the ADGZ, and ordered a further 25 vehicles.

The “s.Sp. Artilleriewagen”. It was a single, self-propelled railcar/ railway wagon, equipped with a 7.5 cm KwK 37 L/24 low-velocity Cannon in a PzKpfw III turret. The turret was also equipped with a coaxial MG 34 Panzerlauf.
Up to 4 extra MG 34s could be operated from the special firing ports (one on each side). There were also a number of additional firing ports, which the crew could use to fire their personal weapons (MP 40s).

The "s.Sp. Artilleriewagen" could either be employed alone or be attached to other wagons to form an Armoured Train.

Its main purpose was patrolling railways to discourage any kind of sabotage, as well as engaging partisans caught red-handed. It was also meant to escort convoys. They were often used as scouts (hence the denomination “Schwerer Spähwagen” - Heavy Scout Wagon), making sure that the tracks had not been sabotaged by preceding the convoy on its route.

Anonymous: American?

No, i’m not american. Please come off anon if you intend to ask further questions.