This is what my friend does. He wet sands all the way down to like an 800 or 1000 grit. This leaves the light nearly opaque. Then he puts on a good layer of clear coat. Once dry the leadlights look like new. The reason for a thick clear coat is you can sand out any minor imperfections and still retain a clear headlight.
my buddy did this to a mutual friends Infiniti. First time he used a restore kit but after a week of good rain it looked terrible again. Since the sanding and clear coat they still look good as new!