All good advice.

Be aware that the green arrows are becoming more commonplace, but they are posted to the right side of the red light on the lightpole. Also, something that takes getting used to is the actual location of the traffic lights. In most cases you will pull up to the intersection (if you are the first car), and then have to crane your neck to watch for the light change.

Don't forget that it is compulsary to purchase a vignette to drive on the autobahns in Austria. There is no such requirement on German autobahns. Also, while the speed limit on the German autobahn is largely a suggestion (130km) and you will not be stopped or ticketed unless you pass through an actual speed limit zone, if you get into an accident and you are exceeding 130km/h, you will be found at least partially at fault, regardless of the circumstances.

Often speed cameras are posted in small towns after the speed limit drops upon entering town (to 50km). When you see the little yellow town sign (with black writing), start to slow down from the 100km speed limit. The sign means 50km/h starts at the sign, not that you start slowing down at that point.