They work for cars too. A couple weeks ago, I was driving (
) on a freeway at 3:30 AM. While I rarely overtake anyone when driving, I came upon a car going slower than I was. I commented to my wife that this guy had the dimmest tail lights I have ever seen, also had some weird white light pointing back at me and if he had headlights they also appeared to be dim. When I caught up to him, I noted that his tail lights were actually just the reflector units, his headlights were just the daylight running lights that automatically come on and that weird white light was from his phone screen (appeared to be Facebook, from the view I had).
Anyway, this moron who was playing with his electronic vibrator while driving in the dark without turning on his headlights was at least reasonably visible because of the reflectors on the rear of his car (inside the tail lights).
But that was a new car. This morning at about 3:15 AM I was passed by an old VW bug that also didn't have its lights on. Those tail light reflectors were a lot more difficult to see, but maybe this is due to the difference between a bike light and car head lights.
And yes, driving at night without using headlights is apparently a "thing" here. No wonder we have so many head-ons and driving off the road fatalities.