Yes I have noticed this with my headlights on. When off they sparkle but on you can still see a bit of haze and etching when the lights are on. I think what we are doing just polishes the surface which reflects outside light so we are seeing an improvement. Maybe we are not going deep enough? I don't know what deep enough is? When the lights are on at night the reflection is coming the other way. My guess is the etching and haze are imbedded in the plastic. The only fix I know of is replacement and I have even seen a few of those haze and etch. My only suggestion is keep them buffed and cleaned. I do mine every time I wax which is monthly.