You may have astigmatism or some other more "mundane" issue there. I see them partially too, but it's astigmatism, because when I put on my glasses they go away. Some do it more than others, but that may be related to the spectrum of the light, which varies quite substantially.

(On that note, here's an old HN post I recall about how to cheaply and easily see light spectrums: https://news.ycombinator.com/item?id=971413 Of course you can't do that with car lights very easily, but you can still check incandescent vs. florescent vs. LED, etc. fairly easily, and perhaps learn to correlate which is which when you see the "rainbows".)