I am going to disassemble my factory tail lights, to paint the unnecessary reflectors black, leaving the outer red plastic alone. this will make the appearance of smoked without any reduction in brightness. i will likely swap to LED at the same time so i don't need any reflectors.

now that summer is coming, leaving your tail lights out on a 95 deg day will make them easy to pry apart. disassembling and painting - 30 minutes. reassembly after dry - 20 minutes. then put together and clamp in the sun for a while, let cool, remove clamps and reinstall. cost? $5 in paint.

what is bright red below is from the silver reflectors inside. my concern with Nightshade is that it is illegal to prevent the reflectors from functioning. all tail lights and headlights have reflectors so if headlights strike them they reflect and the car is visible - even if your lights are not on, i.e. parked. painting the interior doesn't compromise the reflectors. if your car was hit while parked, your insurance could drop you because you purposely defeated a safety feature - the reflectors.