While it may be harder and more expensive to do a plant tour in Europe (if flying over from the US), we have one here!
I still run into fellow enthusiasts who don't realize all of the X model cars are made here in the US, at the Spartanburg plant! I had a chance to go and do the tour and thoroughly enjoyed the whole experience.
While I have watched the assembly videos, it's an entirely different thing to be in the middle of it all. Robot arms all over, assembly lines of cars going everywhere including multiple layers overhead!
If you ever get a chance, make sure to go and check it out! Plus, there is the BMW Car Club of America museum nearby, and the BMW M performance school too! (hint hint for coming content!)