HAHA That happened to me once too. At first I was mad because it startled me and I almost hit a parked car, then I realized it was a convertible full of college girls and the cute one with her arm still stretched out yelled "Nice ass!" as they continued down the road. Irritated or flattered? I think it was a little bit of both.

I got hit by a glass soft drink bottle with the lid screwed on real tight one time. Hit me in the small of my back and left a bruise the size of a dinner plate. I tried to catch the hoopty Chevette that the bottle came from, but there was no traffic and they lost me. I thought I had been hit with a rock until I saw the bottle spinning in the road.

This next incident involves something coming out of a vehicle, but not being thrown.
One time I was riding down a busy, two lane, one way road with cars parked on both sides. I had moved to the left lane because I was going to turn left soon. A panel van started to pass me and I was really squeezed between the van and parked cars. As the drivers open window got next to me the drivers pit bull ran across his lap and started barking and snapping inches from my face! I was only going a little slower than the van so I had to hit my brakes hard to get away from the dog, since the owner didn't seem too concerned. I could feel the dogs breath and had dog spit on my face! I was always on the lookout for loose dogs in people's yards but never imagined that situation.

On the other hand, I've had more people yell nice things at me than be jerks. I used to get "Way to go!" and "Nice bike!" quite a bit. I've done it myself to other bikers, but got tired of getting the finger.