I've had things thrown at me (empty cans or other trash) but nothing heavy.
I've also managed to catch some rude drivers. One almost sideswiped me onetime. I hit my AirZounds horn and the guy just flipped me off. I looked and saw the traffic light up ahead was changing to red. I started to sprint to the car.
His car stopped at the light and I knew I was going to catch him. He knew it too. I could see him watching me in his rear-view mirror.
Just as I was pulling up alongside his car, he peeled out and crossed the intersection THROUGH THE RED LIGHT! Promptly causing his car to be broadsided by opposing traffic! Luckily noone was hurt. The police were called and he was found totally at fault.