Very important driving rules in Germany for non-motorway driving:
If you see a yellow diamond sign to the right of the road at a junction, it means you have right of way. That sign is valid until you see another sign (in other words, you might not get a sign at each junction).
When you enter a town or village (and see the yellow town name sign that shows you're entering the municipal area), the default speed limit is 50 kmph, in front of schools etc it might fall to 30 kmph.
German drivers speed appallingly, for all the fact that they're 'good' drivers. DH mentioned to a friend the other day that we'd copped a 20 euros fine because the speed limit had dropped suddenly on the motorway and a speed camera was directly after the sign (yes, the authorities will do this on purpose) and the friend said 'oh yeah, I get 12 to 15 of those a year!' I swear he was proud of the fact - he normally does about 160 kmph on the motorway.
This is the biggie: if there is no sign giving priority or for giving way, you automatically give way to the car on the right. Learners are taught rechts vor links - right before left. Often there will be no give-way markings on the road itself.
It's actually carefully defined by law how long you get to overtake on motorways before you have to pull in to your lane again - my memory is 30 seconds on the motorway for cars and 45 seconds for lorries. Yes, you will get flashed by the headlights of the driver behind if you spend ages overtaking in the middle lane. I just avoid the left-hand lane altogether (the fast lane) because it's full of lunatics in Audis.
There is actually a law stating that BMW drivers will have their cars taken away from them if they drive carefully, and all BMW owners are very careful to adhere to this regulation. *
- This is not true. It just feels like it.
Best of luck!