I drive this area very frequently; and used to take train and regional bus when I was younger.

I find the drive fairly easy; however I did learn to drive in Germany and am very comfortable driving there.

My thoughts, combined with experience from my family members....

- the drive from MUC to Garmisch can be relatively straight forward EXCEPT for the bit where the Autobahn seems to peter out in Munchen and reconnects on the other side. (I use A92-A9-A95) It's easy for me, but my parents always seem to get turned around (they didn't spend as much time driving in that area as I have). You can also try the ring road route which circumvents the city, but again, the numbers change so you will need to keep an eye out if you don't want to find yourself heading to Bad Reichenhall or Bodensee by accident!

- the drive from Garmisch to Oberammergau and onwards to Fussen is again quite easy. The only challenge can be when the tunnel in/out of Garmisch gets busy. Recently I left on the first full day of all German school holiday, and the tailback to get into Garmisch via the tunnel was about 45 minutes, according to the radio

- I always keep Bayern 3 on the radio to listen to traffic tailbacks/reports; if you understand German it is very useful

- as you have already seen, you will need a vignette to drive in Austria. If you are going to Innsbruck for the day you can stop at the gas station right at the border past Mittenwald to purchase one

- re road etiquette - be aware of signage. The signs in Germany are different than in America, so learn those. I also heard a radio report about German road signs and how we have far too many, so it can be distracting to drivers new to the area.

- I love driving the Autobahn compared to the interstates in America. But the difference is that on the Autobahn there is no time to 'shoulder check' as one learns in America. I use my mirrors extensively to drive and shift lanes while in Germany. (And my colleagues always know when I have recently returned from Germany as they find my driving more confident in America after I have been on the Autobahn)

- when returning the car at MUC you may find it easiest to follow the signs all the way around the airport towards the exit. You will find the petrol station coming away from the airport, not driving towards it (but it is on airport grounds). Exit and make your way back to the terminal

I personally rarely take a map (map #13 of our Germany road map series is falling into bits and has been taped together too many times; the roads are all in my head now anyways). But I do like 'Links und Rechts der Autobahn', which is now online at http://www.linksundrechts.com/ and can be set to English. You may find it useful