Do consider going to one of the spa towns for a night or 2. We enjoyed Marianske Lazne (Marienbad), which is a bit smaller than Karlovy Vary. There were concerts in the evenings during the summer, beautiful parks, and good, inexpensive restaurants. The spa treatments were quite different from spas in North America, and were, well, . . . interesting; but you don't need to use the spas to enjoy the place. In Prague, we've rented apartments several times from http://www.marys.cz/index-net.asp and obtained opera tickets through their service as well. Never had a problem driving or parking.

Carol in Boulder, Colorado