The link there doesn't work.
Also, how does this effect people getting ridiculously larger width wheels and stretching smaller tyres onto them? 215s on a 10 inch rim are legal under this, or is there more to it than that?
Don't kill me but they are going on a S4 RX7 (if they fit - they should). Car is being set up for sprints, hillclimbs etc.
I'll see about pics if you are interested. B)