If you have played my game, you will have noticed I added 4 “lanes” to it. Currently, I am making it so the vehicle changes size when changing lanes, as if it is getting closer or farther. While I was able to, the problem seems that the points aren’t being scaled with it, and therefore, the wheels don’t change position relative to the scale. I am using both non-physics Scaling and physics Shape Scaling.
I can’t comment on your non/physics scaling solutions and with no screenshots of what you’ve done, can’t tell if you’ve tried this extension. I don’t know if it will solve your problem though, just something to try.
As far as I know, everything gets scaled with the sprite, but when you have already created the joints, they need to be removed and recreated.