well everybody knows that a car runs on 12v, and well what do you know, a pc runs on 12v
but in a car : Red = 12v, black = ground
PC: Yellow = 12v, Black = Ground
so connect yellow to red, and black to black (from the molex that you would usually connect inside the pc), and it should work
and about the brightness, uv lights are not that bright, so no worries there, and how would anybody know if its there, if your trunk is closed, and when its open, who would care, becasue for all they could know, you just got one sick arse flashlight