I used the Mcguires head light restore kit (about $20) on the plastic lens which were quite oxidized. Took about 45 minutes to do both lights. It's been 18 months and my lights still look clear and new. I go over the lens every 6 weeks or so with the Mcguires protectant, takes less than a minute per light, it keeps them looking great. With the initial kit it will probably do 6 or 8 lights. You get a bottle of protectant with the kit which lasts quite awhile. You can buy more, it's not expensive. I recommend the Mcguires kit, does a great job and lasts.