Take it that you are aware that automotive lights have to achieve a stated level of lumens - not sure what these values are though.
I'm guessing that this is for newer vehicles? I know that my 1951 Bond was originally fitted with one rear lamp (sharing its glow between the red rear lens and lighting the number plate) that had a bulb of 3W. And the lens pointed more upward than backward!
I took it for MoT, when I first got it in 2009 - still with no indicators, no brakelight, and no dip to the headlamps. I showed the guy the original circuit diagram, and he passed it.
(And no, it isn't like that now: for my own safety, it has three tail lamps, a brake light, and flashers.)