Two more facts regarding driving:
-If mainly in Germany get a Diesel, otherwise you'll be losing a lot of money on fuel.
-Try to do the long distances (more than 200 kms) on the weekends (trucks aren't alloed on weekends) or after 7PM (rush hour), otherwise you'll spend a lot of time in traffic jams. Two of the three most importans Autobahnen in Southern Germany (A6 from Nürnberg to Mannheim via Heilbronn and the A8 from Munich to Karlsruhe via Stuttgart) are under HEAVY construction right now.