DIY tire-rotators will likely have noticed, our wheel lug bolts each are two trapped-together but separate pieces. My brain is nearly 50 years out of mechanical engineering design class, and my later professional career didn't use those skills, so I pretty much forget why these fancy bolts are better. But I do know they have a nice smooth even feel when being tightened. I guess the clamping force on the alloy wheel is nice and perpendicular without any twisted warping? Or something like that? The quirk part - after my recent springtime rotation, the next couple times I did a max-steering-lock parking maneuver, there was a thunk/clunk or two from the front. But never any in the week of driving since. Maybe this was the forces on the lug bolts evening out? What do you smart theoreticians out there have to say?