The bottom line is, even the parents of these kids don't want them playing outside their own house. They don't want
their cars dented or scratched with high velocity balls. They don't want
their pretty flowers in
their front gardens trampled on. They want to be able to sit in their front living room and watch the news etc. in peace after their evening meal, without
their front windows and doors sounding like the walls of a squash court. So they send them out to play outside your house, to damage your property.
The thing is, you can't speak to these kind of kids, who actually come from parents, who don't even have respect for other peoples property. The message is never taught to them in the first place. And if the parent don't get it then neither will they.
All the Gardai will do, is tell them to move on. But that's fine until the next evening, when it's the same thing all over again. You probably need to move as that is no situation to live in, plus who in their right mind would want to live beside people like this for the rest of their days. And that is no disrespect to you or your wife. However, in the meantime, might I suggest the erection of a CCTV angled to protect your property. You must display a notice that there is a surveillance camera in operation for the purposes of personal protection. Then draw their attention to it and tell them that should they damage your property you will have evidence and will sue them for criminal damage. Might help. Might not. Hope it does. At least when they say in future "oh well it wasn't my little angel, he/she is a good boy/girl and wouldn't do that", you can say "well, hey, guess what, I have the evidence, dispute that!!