If the police question you, tell them what the kids were doing, and tell them (truthfully) what you said to the kids. If that doesn't work, and you're cautioned, get in touch with a lawyer, as you are completely in the right here. Do you have any proof / evidence that the kids scratched your car? Do they have any proof / evidence that you swore at them?
Grr... I hate mouthy little brats... and their parents, who think the sun shines out of their arses.