I polished my headlights as they become so yellow and light output was poor. Here is a picture to see the difference: I spent 1 hour with cordless Bosch drill and Meguiar's 1 step headlight restoration kit (G1900) and a bottle of water. Water was for me not for the work. I would say that result is more than obvious. I am pretty pleased with it. Picture is provided with courtesy of my youngest daughter.