I’ll tell ya how the big boys do it, might spark some ideas. Reminds me when I was on the Boeing Dreamliner assemble line couple years ago in Charleston, SC. I was working the rear cargo door that was not coming together correctly, tolerances were accumulating. Looked at the Engineering and some ding dong put the primary datum off the airplane, the secondary was the contour of the composite skin, the tertiary holes in the door edge frame. We had no idea how to find the primary off the airplane. I called design in Seattle and asked what the %$#&#* were you guy’s thinking and a ME helped come up with the idea that worked in Seattle, a bigger better line with laser coming off the factory walls. All we had was a portable so we built an axis off the secondary and tertiary ignored the primary to find out issues, tool up to them, control the tolerance stack-ups. This is what happens when you try and build the first ever “paperless” airplane in the world, no drawings, just tolerances in 3d models.
So there are remote systems with targets you place at the center of the chassis datum’s, if you know them to develop an 3d axis, of symmetry. From that axis there is software that will upload points to a 3d model from targets you place and shoot anywhere. You end up with a 3d model of points showing tolerance accumulations for tracking alignment of the tires per-say. Now that’s precision that has been around for decades I am sure most big UTV factories are capable of as should their dealers.
900XP my guess is the trailing arms chassis lugs are jig located and the tightly machines radius rods are used to locate the spindle, hub, rim, front ones are jig located too. From there tolerance will accumulate to the rim, so using Steve’s method will capture it, the rim would be a better target hard point than the tire. Steve’s method is a good one; you just have to make some assumptions based on your car being symmetrical or not and correct for it.
Shoot me a link to that laser please so we can check it out.