Once in Germany you can travel by train, car, bus, or air. Travel by train is the most relaxing and often fastest way to go. The Deutsche Bahn (German Railways) serves most destinations with great frequency, speed, and comfort. Train stations are in the city center, and served by extensive intercity public transportation networks. Domestic air travel can be cheaper than the train, especially between bigger cities. Air Berlin and Germanwings offer low fares on inter-German routes.
All major car-rental companies are represented in Germany. Gasoline is expensive (about €5.96 per gallon), and parking in major cities can be difficult. Germany has one of the world's best maintained and most extensive highway systems, and a car gives you the flexibility to explore on your own, particularly in less densely populated areas. Most cars in Germany have manual transmission. If you are going to drive, be sure to familiarize yourself with the rules of the road in Germany. And, while it is true that some stretches of the autobahn have no speed limit, you'll need to be sure you know where that does and does not apply as you drive.