This is the place to go!
http://www.autostadt.com/info/cda/ma...06,2~1,00.html
Don`t forget to visit this museum in Wolfsburg while you are there!!
http://automuseum.volkswagen.de/
I have been there a couple of years ago, and it was fantastic!
You can take a guided tour around the factory as well! (You will probably need two days in Wolfsburg to see all of Autostadt and the VW museum.