I have visited the Phaeton assembly plant in Dresden several times, and thoroughly enjoyed each visit. The building and grounds are beautiful, and the whole process of both making and selling Phaetons is totally different than that for any other car in the world.
I have put together some photos, to provide a bit of a 'tour' for folks who have not yet been to Dresden. I hope you find them informative. If you would like to visit the factory, they are very much 'visitor oriented' - the factory is open about 10 to 12 hours a day for visitors, and there are two possible ways to make a tour: