Only once, it was a hard plastic cup. Missed.
Was a bunch of kids in a car, Sunday afternoon. Car came up behind me as I entered a small town, was a narrow country road with no paved shoulder. I was meeting traffic, so the car behind me had to slow down to pass. Someone shouted from the car as they drove by, and hear came the cup.
Couldn't read license plate, since had on sunglasses, not my prescription glasses.