I bought a set of Chinese headlights for a friends Chevy Venture van to replace his heavily clouded OEM'S originals that didn't seem to clear up. Excellent fit and appearance on the new Chinese ones. Now, we would like to find a protective coating to reduce the chances that the NEW lights will cloud up. What do people suggest as a protectant to keep the lights clear? Opinions please? I hate to see the same problem in 6 months! Thanks.