The four-door streamlined body designed by engineer Karl Jenschke was manufactured in Steyr, a 1933 prototype was assembled by Gläser-Karosserie GmbH in Dresden, Germany.

[2] A four-door saloon, two-door convertible, and a bare chassis were available, in addition to a light commercial model called the Steyr 110.

Though not high-powered they could easily climb the Austrian Alpine mountain passes, demonstrated by the Salzburg governor Franz Rehrl, when on 22 September 1934 he and engineer Franz Wallack travelled the Grossglockner High Alpine Road driving a Steyr 100, about one year before the official opening.

In 1935-36 the Austrian travel writer Max Reisch crossed Farther India (Burma, Thailand, and Laos) in a Steyr 100 and continued his journey through the United States.

In late 1937 the grille was redesigned to match the larger 220 model, losing the central bar but gaining a "200" script, and of a convex rather than concave shape.