I've been enjoying and learning from the comments and suggestions here ... and I fully expect to do my own detailed research, not ask others to do it for me. What we're seeking are key suggestions for best base(s) for day driving trips on smaller, interesting roads, starting from Stuttgart and generally heading to France.
We are two experienced European travelers (60s) who have not spent much time in Germany as yet. Like a few others here we are picking up a new car (Porsche Boxter) at the factory in Stuttgart, then driving for about two weeks before returning the car to the factory and taking off for Italy and Greece.
During these two weeks we also plan, if time allows, driving into France to explore the Lorraine and Alsace regions.
Germany so far is a mystery I'd like your collective help in unraveling!