After leaving school and finishing military service, he began a career as a professional motorcycle and auto racer.
The same year, he signed as an engineer apprentice with Auto Union, and also joined the National Socialist Motor Corps.
He also began racing again, designing and in his own workshop constructing a Formula Three racer with a 500 cc (31 cu in) motorcycle engine, akin to the Cooper 500.
In the early the 1950s, Polensky began to concentrate increasingly on sports car races.
In 1955, he was shared a Porsche 550 with journalist Richard von Frankenberg, coming fourth overall and earning a class win.