It's the country that exports most cars. I did not know how to paraphrase it better not giving the name away, but given your information, I fixed the clue. Thanks!
I'm not sure it's correct to say that Gdansk/Danzig was a Polish city in the years leading up to WWII. Wikipedia says that Poland had certain special economic rights with regard to Danzig at this time, but it also says that the population was 98% German and that Poland built the seaport of Gdynia because it needed "a port city it was in complete control of, economically and politically", which was not the case with Danzig.