Well, my suggestion is to do 2 destinations - since there is no way you can do 4 and actually see an

Train is not necessarily more expensive car rental discounts nyc than a car. If you are thinking mainly car rental discounts nyc of stays in cities, consider that the car is useless for the time that you are in the cities. Assume $30 per day on the rental. A three day stay in Prague will cost $90 on the car rental plus the parking fee (probably about the same price for a 24 hour period). car rental discounts nyc To these costs, add the fuel costs while you are traveling. Fuel is about twice as expensive as in the States.
I've added the cities and it gave me a total of 215.60 EUR plus the car rental that I've previously saw, it gives me a total of around 530 EUR, divided by 4 it's less than what I've found by train or plane.
Also be sure you are getting a rental car quote from a company that allows cars to travel into Eastern European Country. car rental discounts nyc Autoeurope, for example, says for a car rented in Germany, "... may not travel into Poland, Hungary, Slovenia, Czech Republic, Slovakia,...."
Many companies won;t let cars - or certain cars (esp the larger ones) be driven into Czech republic car rental discounts nyc or Poland. And if you do so your insurance will be invalid - so if anything happens to the car it comes directly out of your pocket. Be sure to ask about this when yo are pricing the car - so there are no surprises when you go to pickup the car.
Places to visit outside of Prague are Cesky Krumlov, Kutna Hora, Karlovy Vary, Terezin. "En route" to Warsaw, stop in Krakow and visit the city, as well as Auschwitz. Lots of day trips from Berlin car rental discounts nyc are listed in Fodors already.
Well, my suggestion is to do 2 destinations - since there is no way you can do 4 and actually see anything. And trying car rental discounts nyc to stuff in still more desinations between the 4 major ones - when you really have only one day in each city - it just foolish IMHO.
I agree with nytraveler. Reduce car rental discounts nyc it to 2 cities. I wouldn t choose to do Frankfurt over any of the others either. I would choose Prague and Berlin or Prague car rental discounts nyc and Krakow, and think about doing a cheap flight from Franfurt to Prg. Czech Airlines flies that route in 1 hour 15 minutes for about 130 RT.
@Michael, they enjoy nature and landscapes also, they also wanna go to museums and see historical places, I've already got a list of what to see in each city, like castles, museums and things like this, if you do have any advice of places to go, we'd love it