My husband and I fly into Zurich mid August and have rented a car for 6 days prior to our Rhine Cruise (starts in Basel, Switzerland and ends in Amsterdam). We are interested in nature hikes, history (WW2- him, castles-me), and cars (him). We have had so many recommendations for the 6 days, I don't know where to go! Would you recommend the Black Forest Area with Stuttgart, Germany- the Mercedes Benz and Porsche museums? Triberg, Germany- cuckoo clocks and waterfalls? Or should we head for Italy and Lake Como? Should we drive a big loop from Zurich up to Stuttgart, over to Baden-Baden and south to Basel? Where to stay? ANY suggestions would be gratefully appreciated. This will be my husband's first time in these countries, so I want him to have a great time!! Thank you!!!