I'm planning on going over to I'Stadt with a buddy to pick up an S5 in June of 2008. As part of this trip, we'll be spending some time at Le Mans for the race, and I figured that as long as I'm in Europe, and enjoying a total immersion in the Automotive experience, I wondered if there is any way to also get tours of the other VAG manufacturing plants.
For example, if I make my way to Italy, can I visit the Lamborghini plant? What about the Bentley plant; Is it possible to see them building the Bentley's by hand?

If anyone has experience in this area, I would appreciate it.