a) I did Munich-->Lake Constance-->Black Forest-->Strasbourg--> Nurburgring-->Munich.
I drove 1224 miles, spent $637 on gas....
b) Is it worth it to go to Paris? My thoughts are that for a West Coaster, it's much easier to reach Paris than to reach Strasbourg. Eastern France has its own charm...
c) You will need a vignette for Switzerland.
d) From what I hear, Sunday Ring dates are crazy. Try and go to the Ring on a weekday (I went on Wednesday/Thursday/Friday). If you need to convince your wife to go to the Ring, tell her that you can go to Cologne for a day trip. There's also a very nice castle in the area (Burg Eltz).
MR "Civic DX" M3
Nurburgring Tested, Wife Approved