travel from nuremberg to prague to munich

All four of you can go anywhere (hop on/hop off) in Bavaria by regional trains, all day (after 9 AM workdays) with a Bayern-Ticket for €29, total, not per person. There is a direct interstate bus from in front of the Nürnberg Hbf to Prague (3h45m). If you reserve ahead (3-92 day) on the Bahn website you can get 2nd class tickets, including reservations, for as low as €19 per adult. Children under 15 are free if included on your ticket. There are also four about 5 hour all regional train connections from Nürnberg to Prague. With a €33 Bayern-Böhmen-Ticket, five people can ride those trains to Pilsen. Pilsen to Prague is another €6 pP with a Czech Rail ticket. And, there are three six hour connection from Prague to Munich. You buy Czech Rail tickets to Pilsen (€6) and use another Bayern-Böhmen-Ticket (bought earlier in Nürnberg). That train stops in Regensburg if you want to get off there. How many of you are adults (15 and over)?

4 adults and no children

Carol, You'll likely find that you'll have some problems if you rent a car in "western" Europe and plan to take it into "eastern" Europe ( eg Czech Republic) as a lot of rental agencies won't allow their vehicles to be taken to the "east". I know when I rented a car in Austria in 2009, I was specifically asked where I intended to take it, and if I was going "east".
Personally I would take the train. I stayed in Regensburg for several nights on my last trip, and left from there to go to Prague by train. Simple and easy.

Use train and bus. Otherwise you will be paying for your car even for days when is parked. Go by Lee's advice and book your travel ahead. It will be much cheaper than car and much less hassle. I was in Germany and Czech Rep. this last December and driving conditions were bad. Snowing almost every day.

I want to echo the others. I was just in Nuremberg and Prague last month and took the express bus between the two. You do not need a car while you are in the cities, so it would be a waste of money. Prague is not a city I would want to handle a car in either. It was snowing every day we were there, but the roads were not bad.

For 4 adults, the bus would cost at least €76. You have to purchase ahead and commit to a specific date and time. It would take 3½ hrs. The regional train takes 5 hrs. You can purchase €33 Bayern-Böhmen ticket anytime, they never sell out. I am told that you can buy the ticket from Pilsen to Prague from the Czech conductor. Tickets are 147 Kc (€6,05 at today's exchange rate; you might need to have Koruna already to pay). Coming back, the bus would only take you to the Nürnberg Hbf. You would have to get to Munich from there. Purchase ahead tickets for Prague to Nürnberg and to Munich by ICEwould be €34 per person. Purchase ahead tickets for Prague to Nürnberg and then ICE to Regensburg would be €24 per person. The train from Prague direct to Munich makes some stops (including a transfer at Schwandorf for people going to Nürnberg). The next stop is Regensburg. Direct trains leave Nürnberg at 6:00 and 14:05. One change connections leave at 9:95 and 17:53. For Munich, direct trains leave Prague at 9:10 and 17:10; one change connections leave at 5:10 and 13:10. All changes are in Schwandorf. As for driving conditions in Bavaria in December. Ask Centennial Frank. He was just there. He took the ICE/bus from Munich to Praque.

I appreciate all the detailed suggestions. I think you have convinced me. I thought there would be advantages with a car and splitting the cost. However clearly no one seems to think that. We have lots of time to plan.

Carol, here is the website for the bus: http://www.eurolines.com/ I believe it also runs from Prague to Munich. These buses mostly stop in front of the main railway station in each city but may also have a second stop in a large city.

Eurolines is not the Bahn. They run buses all over Europe, but to Prague on a much less frequent schelule than the Bahn.