Being involved in both motorsport and climbing, this is somethign I'd wanted to check out for quite a while.
What I'm thinking of is a wicked-early hike/climb up to a small sub-peak on the tundra to the north of the summit-proper, and watching what we can of the rally before retreating.
Apart from the obvious rules regarding the course (we have no plans of getting near the road), are things more tightly regulated on the rest of the mountian that day? I don't suppose we'd need an event ticket, would we?