The SdKfz 221 was the first in Germany's only family of four-wheeled armored cars. It was designed on the basis of a sPkw I Horch 801 chassis that was standardized for military use. In contrast to many pre-war armored cars, it featured a rear-mounted engine (which gave it a distinctly modern appearance for a mid-1930s vehicle), four-wheel drive and front-wheel steering. Armor protection was light, but the SdKfz 221 benefitted from a heavily sloped hull which made it immune to calibres up to 8 mm (.30 mm). Firepower was modest, and consisted of a sole turret-mounted MG 34 though this was later upgraded into a 2-cm KwK 30/38 in the SdKfz 222 which aside from the bigger gun and turret was otherwise broadly similar. The SdKfz 221/222 was primarily issued to the reconnaissance batallions of Panzer divisions and gave a good account of itself in the early Blitzkrieg campaigns in Western Europe where road networks were well developed. It was less succesful on the more difficult off-road terrain of the Russia and North Africa compared to its six- and eight-wheeled counterparts. Nevertheless production continued up to 1944 for some radio car variants. Other users included China, Bulgaria, and Romania.

The Leichter Panzerspähwagen (MG) (SdKfz 221) entered production in 1935 and despite the entry of its successor shortly afterward, remained in production until 1940, with no variants produced although many were modified in the field from 1942 with a 2.8-cm sPzB41 cannon in a modified turret. The Leichter Panzerspähwagen (2cm) (SdKfz 222) was the major production version and was broadly similar aside from the larger turret and gun. Wartime modifications included a Horch 3.8 engine and increased frontal armor (to 30 mm). A dedicated radio car version without a turret but which retained the MG 34 gun was known as the SdKfz 223 with a frame aerial and went through similar modifications as the SdKfz 222. A related development were the SdKfz 260 medium- (rod antenna) and and SdKfz 261 long-range (frame antenna) radio cars, which were unarmed aside from crew-carried weapons