It is not easy to renovate the headlights, but it is not difficult either. If only the outer and inner layers are yellowing and aging, just polish off the surface and then apply a UV layer to make it look brand new. However, the inner layer of the lampshade will produce oil film and dirt after long-term use. How to deal with it? The internal problems of the crown headlights require special treatment, otherwise strange phenomena will occur. The previous owner may not have taken care of the dirt and oil film inside the lampshade, resulting in a rough and uneven surface. If your car lights were polished like this, would you still accept it?