We Have Wanted This For A Long Time. The Aventador Mod Has It And Stuff, So It's Not That Hard To Implement.
I was also wondering about this recently. Maybe the way it's implemented in the Aventador is hard, but shouldn't be too hard to implement it in game on the LUA side. Making a smooth transition between the on and off textures, and smooth brightness changes. But idk that much about LUA.
Depends what kind of model probably. A whole car and a modified vanilla bumper can both be models found in mods but the difference in skill and effort they take is huge. The hard part here would be figuring out what exactly you need to do to achieve that effect. From there it should be easy as long as you know the basics of LUA.
i mite try to make this work but yes it should be part of the game. ive seen the game take some mods people make and use them as oficial content so if someone (or me/ can make this work well they will probably use it!