If they almost hit you it puts a huge scare into them as well, and that's something you just have to let go. If they carelessly skim you and don't even know it, they need to be told politely.
If they throw an orange at you while they're going about 50, and it hits you in the leg, causing you to have to walk the rest of the way in agony, well, then you were me a few years ago.
I still remember looking into the eyes of one of the laughing, screaming guys in the back of the Jeep and watching his face melt from pure evil laughter to, "oh crap. We know each other."
I've never seen a smile turn to a look of fright faster.
I let it go, however. I was very young and didn't want to get into it with four guys in a Jeep. I'm sure they sweated it for awhile, though, wondering if cops were coming to their homes. I'm sure the guy I recognized said, "Shut up, guys. I know that guy."
Had they known who I was they probably wouldn't have thrown it, but they only saw the back of me.
And forget the bruise and the pain. The worst part was that the orange, after exploding, rolled back into the street and got ran over. I could have eaten it!
