I don't know what it is, I encountered it in BX and Moonhawk. When the light goes out, some of the faces continue to burn for some reason. Maybe someone has some idea what this might be related to?
I encountered the same issue when trying to modify the Moonhawk. I had to split the brake lights into two separate meshes which seemed to fix the issue but ultimately breaks every mod made for the Moonhawk. I hope you can find a way to fix it.
honestly i don't understand why the devs didn't also add the lights to the I Series, since it was the car that was used to tease the new fade effect.
While I'm doing this, I've come to the conclusion that they just didn't have time. Some of vehicles are ready for the implementation of this system, and some, as I showed above, will not work without making major changes that will take a lot more time. But I hope that I can do at least what has already been adapted.
I have done the D-Series original taillights if you want it I also had the idea of having the taillights get damaged and still work but without the red color unless it breaks off completely