I think you would have answered your own question if you had stopped with the first two words of the your following sentence

One possibility is to head down to the twin cities of Garmisch-Partenkirchen on the German/Austrian border. You have the A95 most of the way without the heavy traffic on the A8 (Munich/Salzberg/Innsbruck). Just outside of Garmisch is the Zugspitze, the highest peak in the Bavarian Alps as well as the Parnaklennham Gorge on the edge of town.

If you want to have some fun on the rural roads, you can skirt Garmisch and the Zugspitze enroute to Reutte and then up to Neuschwenstein Castle. Alternatively, head south through the mountains on B2 and down into Innsbruck, a wonderful little city. It's about 2 hours Munich-Innsbruck depending on traffic and where you are going. Note that this latter route keeps you on secondary highway so a traffic decal is not necessary (you have to have a decal for driving on the A-bahn in Austria)