comments:
XLB135 posted on r/miata2d
So annoying, but they definitely just semi-eyeballed it. We bought a car that was like this, where the entire plate mount was off-center by maybe an inch. It wasn't noticeable when we looked at the car, but as a detailer, bringing the car home and then spending the first couple days establishing a paint thickness baseline for detailing, etc., it became very apparent. We ended up buying one of these kits and re-drilling a perfectly centered mount. I wouldn't overthink the existing holes unless they really bother you. It's soft plastic down there with nothing behind it. If you want, you can probably find some paint-matched bumper plugs just to plug them up before a mount option like what I linked.