Hi: I am planning a trip with my 18 yr old daughter to Europe. I had planned to rent a car in Frankfurt rather than the train to travel the Romantic trade route so we can see all the smaller towns at our leisure. I also wondered about camping or would most recommend hostels as a better option and experience? I also would like some travellers opinions on whether it would be better to only use the care until Munich and then get a railpass for vienna and prague before we continue to Italy?
If you post your complete itinerary (as much of it as you have), people can give better advice. How long is your trip, and what time of year? Seeing Germany, Vienna, Prague, and Italy will take time, unless you just want a blur of highways and train stations. For getting between Munich, Vienna, and Prague on the train, a rail pass will cost more than point-to-point train tickets bought in advance. To get schedules for all of Europe, and to buy tickets for journeys starting or ending in Germany, use the Bahn website following Rick's tutorial: http://www.ricksteves.com/plan/tips/db_tips.htm
A car from Frankfurt to Munich might make sense so you can stop when you want. Trains from Munich to Prague and Vienna would probably be best because after awhile, you are going to get tired of driving and want a break. Usually trains will get you there faster than driving, especially popular routes like Munich/Vienna/Prague. Also, dropping off a car in a different country than you picked it up usually is an extra 100 euros as a drop fee. As the other person said, rail pass is probably not a good option if you know your dates and times you can buy advance purchase and save money. If you want flexibility, I think there is a rail pass for these three cities that gives you a one way to all three that might make sense for you. Details are on this website. Good luck!!