What to do with 3 days to get from Munich to Dussledorf?

I would suggest that you plan to spend all of your free time in Munich. It is a wonderful city and will give you a good taste of Bavaria (southern Germany).
The art museums are excellent, The Residenz, home to the Wittelsbach family who ruled Bavaria for a long time, Nymphenburg Palace, Deutsches Museum--all worth a visit. Good food and drink can be found almost everywhere in Munich, depending on what you would like to have.
On a good clear day, you can see the Alps.
Look at a visit to the MarianPlatz, the Ratzkellar there for a nice taste of local eating and drinking/
You can't go wrong in Munich. (I hope:-)

You really don't have that much time in Munich. You arrive Thursday afternoon, check in to a hotel. That gives you Thursday evening, all day Friday and Saturday morning. Saturday afternoon you should head to Duesseldorf, its a 4:45 hour train ride on the fastest direct train. You can get a hotel in Duesseldorf Saturday night and ride to the airport on the S-Bahn Sunday morning for your flight.

Hi,

I would spend that time in Munich, unless you are absolutely bent on seeing something specifically historical en route, such as in Frankfurt, Koblenz, Ulm, Stuttgart, etc. There is also the night train connection from Munich to Düsseldorf on the CNL.

Looks like the recommendation is to just maximize time in Munich. Thanks for the tip about the overnight train - that will really help us maximize the little time we have!

Night train right before a flight back over the Atlantic? They are not known for providing the most restful sleep environment. The train will make 11 stops through the night between Munich and Duesseldorf Hbf. If you do decide to go for it, looks like you could get a deluxe double cabin for 239 euro if you buy NOW on line at ww.bahn.com. That is just a 20 euro upcharge from an economy double, probably worth it.
For your connection at Duesseldorf Hbf, take the S-11 train to the airport. That will take you right to the terminal. Duesseldorf Flughafen Terminal is the station name. All other trains go to the main airport station (Duesseldorf Flughafen), which is out by the end of the runway and connected to the terminal by a skytrain system.

Hi,

You don't mention where in the US you'll be flying to from Düsseldorf (DUS). If it's to the west coast, I'm counting on a flight of 10.5 to 11 hrs and would certainly would take the CNL night train option since this route offers the sleeperette (Ruhesessel) option. I've done that option a couple of times, no problems sleeping, and much cheaper than a sleeper. You'll have to decide whether that option is better or taking a late ICE direct to Düsseldorf Hbf. If no night train, then stay at a small hotel near the station, ca 2 mins. Take the U-Bahn to DUS the next morning....all very convenient from Düsseldorf Hbf.

If it helps in offering advice, I'll be flying back home on a non-stop flight to Chicago, leaving Dussledorf at 10am. The flight will be just over 9 hours, but I'll be boarding a flight to Charlotte a few hours later for a conference (which came up after the flights to and from Europe were already booked) so I'll have a whole day on planes and/or at airports on that Sunday regardless of how much sleep I potentially get (or do not get) on an overnight train.

Thanks again - I really appreciate everyone's input!