It should work well with the rear wheels, but with the front wheels it’s another matter, if I tried to isolate just Y (in local or world space) I would get incorrect values. Since Z also moves, Y and X need to change values to maintain the effect of the wheel turning and spinning at the same time. In the end, using just the Y value, the wheel animation would spin in random directions. If I used Z for the Kingpin, it would also give me the same problem.
In any case, I need to be sure about all those previous doubts before making the purchase. (I’m not saying that the plugin isn’t worth this amount, but that it’s an expensive investment for an indie developer).