Car or Train in Germany

Use the train; definitely use the train. You don't mention the size of your group, but if you are seriously considering renting a car in Germany I will assume it is 4 or less. The train cost will probably be a wash with the car rental, but I still believe the train will be your best bet. It will get you comfortably to all of your German destinations with virtually no hassle. Once there, walk or use great public transportation. Having a car in any large European city is problematic, simply from the perspective of finding a convenient parking space.

Train, definitely train. So much easier than messing with a car.

"Input appreciated!"

My input isn't about how to accomplish your plan but how you might adjust it. Will you be returning to France? What is included "the rest of the trip"?

You only have 5 days, and you are traveling some long distances - lots of ground travel time - and you've chosen places that tend to be mobbed with tourists in July (R'burg, N'stein, Romantic Road.) The round trip to N'stein from Munich takes nearly 5 hours, all for an overcrowded, rushed, 30-minute tour of the "castle" (which really is a late 19th-century palace with a fake castle exterior.)

So if you are heading to some other country after Germany, you ought to consider exploring some of the amazing places near Heidelberg, IMO.

Rhine River Castles: http://www.romantischer-rhein.de/en/what-to-see-and-do/culture/castles/map-overview-castles/
Ludwigsburg Palace: http://www.schloss-ludwigsburg.de/en/home/

Germany is an absolute treasure trove if you explore places that aren't covered so heavily in guidebooks like Rick Steves'. Below are some less overrun old-world towns similar to Rothenburg and that are closer to Heidelberg... in these places the tourists tend to be Germans and European - you won't be rubbing elbows with so many international tourists:

Hirschhorn
Michelstadt
Calw
Miltenberg
Ladenburg
Bad Wimpfen
Michelstadt
Besigheim
Heppenheim

These old-world wine towns along the Rhine River towns aren't far from Heidelberg either:
Oberwesel
Braubach (home of Marksburg Castle)
Boppard

I believe you can reach every one of the places I mentioned by train (not that you have time for all of them!)

I much prefer to travel by train in Germany but your itinerary is not great by train. Heidelberg to Rothenburg is a cumbersome 3.5-4 hours by train/bus with lots of transfers. Rothenburg to Munich is 3-3.5 hours by train with a couple transfers. Munich to Neuschwanstein is over 2 hours each way.

Although I am a fan of Rothenburg, I would question if it fits in this itinerary. If you keep it, a car might be good for those couple of days as you describe.

Russ make some good points.

Hi,

With the planned itinerary you have, take the train. If your itinerary included going out to villages and towns in Brandenburg, the Greater-Berlin area, or Mecklenburg, then I would suggest a rental car as being much more convenient and handy, with which you can visit villages along the Landstraße in the old Mark Brandenburg.

Consider doing the Romantic Road.
http://www.fodors.com/world/europe/germany/the-romantic-road

Some tours may be available.

If you're concerned by the multiple train connections that Gary mentioned, then get more detail using the DB link at Looking Up Train Schedules and Routes Online. I would consider picking up a car when departing from Heidelberg and try to use it for Neuschwanstein as well, before arriving in Munich. The Munich-Dachau side trip is just a 20-minute ride on the cheap S-Bahn system, while Munich-Fuessen by train takes 2 hours each way. Then train Munich-Venice.

I've traveled extensively in Bavaria and southern Germany in the past 15 years, and the rail system, one of the best in Europe, works well. For every trip in the last 10 or so years, I have compared the cost of train tickets (Savings Fares, regional passes, etc) to the cost of renting a car, and a rental car has never been close to competitive with rail travel. Some people think car travel is more convenient, but convenience has a price.

BTW, ViaMichelin says the quickest way from Munich to Füssen by car take 2 hours, and that's assuming you don't make a wrong turn or get slowed down in traffic. I think the train would be a more reliable way to go, particularly if you commit to a reserved tour time.

We rented a car at the Munich airport to go to Rothenburg, Nuremberg, and dropped it in Dresden. My husband enjoyed the Autobahn experience, and we enjoyed the little bit more freedom the car gave us (what time we left, how long we could stay somewhere etc.) We did not have a car in Munich and found it very easy to visit Dachau via the S-Bahn.