Two weeks just isn't enough time

This morning we met for breakfast and sketched out an itinerary. While we both favor more impromptu traveling, we realized that we need to have some idea of when we'll be where in order to fit in what we have set out to do, and also so Bob's relatives know what we'll be up to. As it stands now:

Day 1 (Monday) - arrive in Stuttgart/Waldenbuch

Day 2 (Tuesday) - Waldenbuch; perhaps tour the Ritter museum and/or Porsche or Mercedes

Day 3 and 4 (Wednesday and Thursday) - Munich (tour BMW one of those days)

Day 5 - (Friday) Ingolstadt (Audi); travel to Berlin

Day 6 and 7 - (Saturday and Sunday) Berlin

Day 8 - (Monday) travel to Wolfsburg; tour Autostadt

Day 9 - (Tuesday) Wolfsburg; tour VW Museum; travel to Waldenbuch

Day 10 - (Wednesday) Waldenbuch

Day 11 - (Thursday) travel to area near Nürburg

Day 12 - (Friday) Nürburgring (Nordschleife); travel part way back to Waldenbuch

Day 13 and 14 - (Saturday and Sunday) - Waldenbuch/Stuttgart

Nordschleife, here I come

I've narrowed down the dates I'm going to drive the Nordschleife--either May 16 or May 20. There is Touristenfahrten in the afternoon and evening on those days. Touristenfahrten, literally tourist drives, are when virtually anyone can drive on the Nordschleife. Tour busses, motorcycles, station wagons, and motorhomes join the likes of Porsches, Lotuses, Ferraris, and Audis on this challenging road. Maybe if I get lucky I'll see this one-of-a-kind car:

Wie ghet es Ihnen?

My high school German is long gone, so I've been listening to German language CDs while driving (I figured listening to these in a German car should help). My work commute is about 13 minutes so I haven't covered a lot, but I can ask for something to eat or drink and inquire about the location of a street or square. 
I'm also going to study through the Mango Languages resource offered by my public library. It seems it has my number, as the introduction to the German section asks "Ever see yourself behind the wheel of a high performance German sports car on the Autobahn?" Hmm, how did they know?

Logistics

Germany is known for its excellent passenger rail system. It's also known for its wonderful roads. We'll probably do some travel by rail, some by car. While it would be great to meander without much of an itinerary, reserving a car might be best done stateside before leaving, so we'll need to know when and where we want to drive. We're also planning to meet up with my friend Mary Jo at some point. Mary Jo's husband, Jim, is on a Fulbright in Austria,. Both of them may join us in Berlin, which would be a blast as Jim is familiar with Berlin and they're both really good company.