In my 5th gen there's a small LED bulb for the ashtray. It only turns on when the parking lamps/headlights are on. I have two blue 10" neons tapped to that same wire (the neons use very little power) They turn on when I turn on my lights, which makes sense since you won't see them during the daytime in which case you don't use your headlights anyways. Just remember to keep it clean, no wires everywhere and not directly shining at you. Under the seats are a good place.