amdx actually said:

I assume that is the wheel and not a hub cap.

The car I will test this out first on is a bimmer with alloy wheels and lug
bolts so both those traits make the task of bolting on a jig easier than if
it were a steel wheel with lug nuts.

I'm guessing your looking for something between 0.5* and 2*, but I want
to know.

I later found this BMW spec which shows that I need accuracy in 1 or 2
minutes ( http://i.cubeupload.com/cfaDWp.jpg ) but how do I convert that 1
and 2 minutes to inches?

Someone said you need accuracy within .01 degrees, that's 1% of 1
degree.

I think he meant inches though.

Good luck getting the 18 year old at the tire shop to do that.
I'd be happy with 10%, being that it is an adjustable characteristic
that can depend on how you want to drive the car, comfort or cornering.

I understand that the alignment shop guy might not care all that much to
get as accurate as he can.

Right now, I think the accuracy needs to be plus or minus one minute for
toe and 2 minutes for camber.

I just don't know how to convert minutes to inches.