It's a matter of degree. Yes they have cars and car infrastructure in Germany and Japan, but not nearly to the same extent as the US. That was OP's original point and question.

You should do more digging, most cities in the US (the middle part anyway) were also set. But they spent the money to buy out plots, tear it down, and build massive infrastructure. Why? Because of what I said: they could afford it on both govt level and personal level. Europe was devastated because of back to back world wars which cost a shit ton. On the other hand the US profited from that. Even when you have relatively green field construction you still have to buy the land and still have to build, aka it's still expensive. I'm just repeating myself so I think I'm out.