Here's the stock rotor and my wheels.
You can see the obvious here. :)
You can see how the rotor center bore is larger than the hub in this picture. The rings I am having machined will take up this slack so as to properly center the rotor. Once everything is in place and the wheel is bolted on, it isn't going anywhere. I'm having the ring machined to provide an "interference" fit which will require it to be installed with a pipe and a hammer. You wouldn't want the ring to slip out of place..
You can see the small area where the pad doesn't contact the rotor, but it is very small.
And here's the rotor installed.
Just another shot to put it into perspective.
Here it is, $74 13" rotors on Z32. - 
