I called *555 late one night, as on the way home, a boy racer in a legnum VR4 nearly collected my family and I only 100M from our house!
I was only doing about 50K (country back road), I suggested to the cops he was well over 120 on a curvy part of the road.
After I pulled left into the gravel, and he very nearly took out my wing mirror, easily 1m over the centreline, I saw him fishtailing down the road, before regaining control. I had hoped he'd plummet down the 50M bank on his side
I called *555 as soon as I got home. I had NO idea of the rego number, just the car, and colour - it HAD to be a VR4 version, as a non turbo could never achieve that speed there.
2 hours later, I was awoken by a call from a cop in a suburb 25 minutes away.
They'd pulled the guy over, asked him why he was travelling in a reckless manner on our road (calling his bluff - I didn't have the rego), and he admitted it was him. The cop asked if I wanted to pursue charges or or if he should just be fined, and given a letter of warning.
I went with the latter, as it's probably more effective for the young guy, and I hope he thinks twice next time. We've all done something silly, and he was honest about it.
I have dash cams now - not so much help at night, but it does show what happens. A good one will show regos from daylight footage.