Almost a headshot.
Several years back I was on I-20 just outside the Perimeter in Atlanta (several lanes wide), when I noticed something bouncing in my peripheral vision up ahead and off to the right. It was a wheel bouncing along out there at 50-60 mph with the flow of traffic, and after that initial moment of WTF, I realized that it had come off the mobile home being towed in the far right lane. It bounced along with traffic for what seemed like forever. Kind of bizarre as people were just changing lanes and passing this lone rolling wheel like it was another car, heh. I saw it meander across about 3 lanes in the rearview and then lost track of it.
Too many idiots out there on the roads ejecting large objects at high speed.