I’ve not tested myself, but looking at the video it would appear that the sim is calculating whether the lights should be ‘shown’ based on the position of only the left eye, so when that is below the line of the bottom of the windshield the lights get ‘turned off’. But of course the right eye is much higher because the head is on its side and can (should be able to!) therefore see the lights!
You can see similar effects with reflections in the water, so maybe lights and reflections are done with a shader pass which is ‘2D only’?
Just theorising… Happy to be told I’m wrong!