The 170 wasn't the top notch Mercedes in the range, rather the opposite. I think it was their entry level and as such it would have been priced for the middle class and possibly the upper echelons of working class.
"The pre-war production of W136 cars and light commercials was around 90,000; production ended in 1942 as all efforts were directed towards the war."
Quote from:
https://en.wikipedia.org/wiki/Mercedes-Benz_W136 A fair amount of these 90000 vehicles were probably exported.
The German population in 1939 was around 68 million.
If we assume that 68000 of the produced vehicles stayed in Germany it would mean one 170 V (any bodywork) for every 1000 Germans or one for every 500 males (of any age). Assume average family has two or three kids and we get one car for every 200 adult males (very rough estimates).
Opel produced more cars before the war, some of them were more luxurious than the 170. There were also other manufacturers. Cars were also imported from other countries.
/ Robin