It has rather something to do with a car rally. The texts say:
XII.R.F.S.T.
30/31 MAI-BRESLAU-1931: 30th/31st May-Breslau (a city)-1931, thus date and place of the happening.
3. REICHSFAHRT: 3rd state ride (or rally).
There is a page on it in the German Wikipedia:
https://de.wikipedia.org/wiki/Reichsfahrt
But the 1931 one in Breslau is not mentioned there.
They were rather long trips where the several brands could show what they were worth.
I am not going to translate all of that page (try Google translate or similar when you want), but it says also that while most of them were organised by the ADAC, some were by the Stahhelm, a more political organisation.