Isn't this a function of how much or little caster that is set into the VW H beam axle. My FF widebody has the suggested amount of caster set in with shims and the wheels appear centered in the wheel wells. Could this also be a factor of the car builder not cutting the pan down to the correct dimension?
On My Speedster the rear passenger side wheel has a different spacing than the drivers side which I have rectified with an additional 1/8" wheel spacer on one side. I have heard all the CMC/FF widebody cars are like this. Others may know more.