Not that it wouldn't be a great time and that they don't deserve it, but the paintball idea could land you in jail. The Police car idea sounds great to me. Even a sign that says "smile your on camera...." might help, or it might make it worse!
Here is what you do...
Put a life sized cardboard cut-out of you in your front yard with a videa camera running. When they drive by the first time it will scare them and they will not throw they eggs until they realize it is fake, and that will make a game out of it for them and they will have to go by a second time to target the cuttout and that's when you catch them on video. My guess is they will not be able to resist coming back to "nail" the "fake you". Like birds landing on a scarecrow to show they aren't afraid of it.
Maybe it's stupid, but that's an idea. Give them a target they can't resist hitting, one that will not be damaged (like broken windows). Sounds like they have already hit everything else.
CR