i was wondering if anyone has had wheels that are made for audi's (smaller bore) machined out to be bigger?

What do these wheels look like? CNCing a circle is not hard and I guess it could be done. Mercedes wheels are hubcentic are Audi wheels?

You don't even really need a CNC to machine a circle. If you get the wheel lined up on a manual lathe, you could put a cutting blade on the lathe and offset it from the centerline of rotation by the radius of your circle. Definately center it in with a mic and the lock the X and Y.

I'll try to find the link that a friend posted on a mailing list of cool mill tricks. You can even mill a sphere with the right fixtures.

here you go, a flycutter fixture. I would probably run the blade closer to a horizontal angle.

The mill head on the top right is what you are interested in. The bottom left fixture isn't required.