I was traveling behind a semi that had a large load of 12' long ~4"' channel steel on a four lane highway near dusk. Lo and behold, a few pieces of steel in the middle of the stack worked their way free and once they fell, the rest of the stack was following. There were steel sticks scattering all over the highway and every car following had no idea which way to go. I only managed to nail one (under car damage mostly) of them but there were something like 15 cars damaged,
I have had a flying loose retread slam my windshield once (boy was that loud and scary and shattered the windshield but no other damage).
I hit a huge raccoon once in my first car, took our my license plate and damaged my bumper. I thought I had hit a dog until I found the dead raccoon.
I was driving in the middle of a busy multi-lane highway pulling a boat when I saw a deer break from the right side to run across the highway. It didn't get far, a car just ahead of me and on my right nailed it and a whole bunch of blood and parts plastered my windshield. I had to very quickly use the washers to clear the windshield in order to change lanes and slow to pull over.
I was on a three lane highway in the middle lane behind a car that had a mattress tied to its roof. It came free, flew off and bounced in front of my car, cleared over my car and hit the car behind me. I had no where to go, there were cars on all sides. Pure luck, it was a little closer or a little further away, I would have hit it for certain.