Traveling in Germany by car

We just got back from Germany on a two week driving adventure. It had been 10 years since driving in Europe (mainly France) so there were a few differences to learn. The one big difference these days is the GPS. While we had the AAA book of maps (all on Germany, 200+ pages) of Germany--it was great for small towns--having the GPS was also a great help. The one thing that I have not seen in "driving in Europe" articles (and admittedly, I've only read a few) is the importance of knowing the Postal Code of the city to which you are. For instance, one of our first problems, was when we were heading to Rothenburg(Germany), was the GPS showed us 4 each "Rothenburg"s....we started scratching our heads and finally looked on our map and noticed the one to which we were heading was Rothenburg o d T (ob der Tauber), but also, in the idex of my map book, for each town, they had the Postal Code....from then on, when entering our next desination in the GPS, we included the Postal Code....WOW, what a difference. Hope this helps some future travelers