Suppose for whatever reason, Nazi Germany survives longer (be it Poland is thrown under the bus, Hitler dies in 1939, a negotiated peace, etc.). My question is, what becomes of the Volkswagen Bug? Will it become a common sight in Germany, or just something the government keeps promising to deliver but never dose?
Well.....firstly, given the fact that one of the Beetle's inventors(one Josef Ganz) had already left Germany fearing persecution, one must imagine how wary Herr Porsche must've been not to get Hitler pissed off at him. Porsche stayed home IOTL, not because of any real love for the Nazi Party but likely because he was either truly afraid to defect to the Allies or felt that he had nowhere to go.
If Porsche ITTL gets worried enough that he may find soon himself purged by the very man who claimed he'd help him become famous(which isn't at all unlikely), and if he happens to be close enough to England somehow, it's almost certain he'd want to leave, therefore making sure that the Beetle gets built outside Germany. As to where he'd go, I'd suggest somewhere like Mexico or Brazil; he could also seek out his old one-time colleague Josef Ganz, wherever he might be(perhaps Switzerland, like OTL?) if he hasn't been killed by the Nazis already.
If Porsche were to stay, however, I still don't see the Beetle ever entering mass production. The Nazis had never intended the Bug to enter mass production, and given that it's roots(even the body design) were in the late Weimar period, somebody could always convince Hitler to jettison ol' Ferry for that reason alone(remember, the Nazis had always hated the Weimar regime for its attempt to be an egalitarian democracy and they wouldn't have wanted to build a car that reminded them of happier times)and hire someone else....who, though, could be debated.