^Keep in mind that Ring Werk is actually at the F1 circuit and not on the full course. They had some sort of race going on the weekend we were there so I didn't see a way to get in to the stands without a ticket. I agree though, I'd love to do a lap on the real North ring one day (unfortunately didn't work out this visit).
They also require you to use a "Ring Card" to make purchases within the "park". We got lunch, put 10 Euros on the card, and had pay with the card. I think we both had like 1.50 Euro leftover that we couldn't use anywhere else, so that was sort of annoying.
Overall though it was really cool inside, and you could tell they spent a lot of money on it. It was just sort of empty all around when we were there.