Thanks,
I went to the visitor's center and saw the displays as well as a video. It was worth it. The actual plant was closed to visitors. They said there is construction so it will be closed until October. They also said there was a prototype in the plant so it was closed for that reason as well.
Among the displays was a racing engine. A V10 3.0 litre with massive throttle plates (one per cylinder inside a huge plenum). That was enough to get excited about by itself.
Beautiful plant. Way nicer than the GM plant I used to work in.