Go to Radio Shack, and ask the people there about the cameras.
Once you have a camera on the driveway, wait. Get plenty of footage of damage to the cars(all of it could be the daughter instead of lori) and then go to the cops. If the cops do not satisfy you in their response, go get a lawyer, and sue them. Sue them hard. In the course of that, they should move away, to hide from the lawyer stuff that will fall out. Make sure when you go to the cops or a lawyer that you take ALL the paperwork from all previous incendants. You saying "last year she did xxx" doesn't hold as much clout as "Here's the police report.. here's the court's decision.."
Good luck. Ignoring it without responding is better than shouting back etc., mainly because you do NOT want it to escalate with small children in the crossfire, and if you respond, then it's just fighting between two sets of folks(in the eyes of the cops).
Get the cameras(they are not that expensive when you consider how much damage has cost you so far...) and get some recorded evidance.