Erick - you should reconsider your trip plans. Anything more than driving four hours per day and you will be wiped DEAD. I have driven 14 hours in one day in the states... it is NOTHING like driving over here. Probably after thre hours you mind will be mush.
EmmDrei is right! Plus driving on the 'Ring on a weekend is nuts. There are soooo many fast cars and crazy race car drivers there. You will be way over here head. It is far better to go there during the week in the afternoon/evening.
Don't drive anywhere on Fridays on the AUobahns. There are always huge stau's on Fridays. My advice would be to head South of Munich - see the Alps or Garmisch. Then maybe drive to Stuttgart (Porsche & MB Museums) and then on up to the Ring. Or you could go to Austria's Gross Glockner Pass or Italy? You really should wait until you get some miles 800 or so before hitting the Ring.
Also... did I understand you first post... you will fly into Munich and then in the afternoon pickup your car? Are you nuts? I know after I fly eight plus hours the first thing I want to do is take a nice shower and a nap. I would pick up your car the following day.
Maybe this will help give you some ideas...
Dackel's European Delivery Museum Guide
http://www.e90post.com/forums/showthread.php?t=494657
Dackel