I would say that change happened much earlier, and was almost complete by 1911 in many US cities. OTOH I had a hard time telling apart cars from 1910s vs 1930s

I would say that change happened much earlier, and was almost complete by 1911 in many US cities. OTOH I had a hard time telling apart cars from 1910s vs 1930s. Around the early/mid 30s a much more modern style of car came on the scene (Ford Phaeton etc. I guess), but I suppose it took a while before the Model-T style vehicles were all replaced.