This article continues the author's previously published investigations in the history of Russian urban transportation and examines a subject unfamiliar even to specialists: efforts to improve passenger cars for Russian streetcars amid the uneasy circumstances of the Soviet Union in the 1920s and 1930s. Apparently, prewar attempts to improve Russian standards for streetcars resulted only in the creation of unique experimental models, of which practically none have survived to the present day. The advancements, innovative ideas, and accumulated practical experience from that time, however, are far from uninteresting from the standpoint of the history of technology.