If your suspicions are correct, that was a feasability study.
Local councils are starting to look at the possibility of using the Australian system here, but then, it's been on the shelf for a number of years.
Look out for cars with 2 drivers wing mirrors too
Basic method, radar type detection, you get a field of "vision" & you know how quickly an object is approaching, subtract your own speed, and bingo, you have the speed on the oncomer.
Most van type studies that I'm aware of have used a
gimbal. So maybe that's what you saw. This setup is more expensive, but more capable because it can be "targetted".
Couple all this with a camera, and you'd better be careful. Of course, bikes are better off with a camera, and an unmarked car isn't always guranteed to turn around after you, that's a safety judgement.
P.S. It's radar, not laser that's been used (so far, to my knowledge). Which makes for fun modifications to your fairing. Not that I'm advocating anything, naturally.