I bought a Sylvania kit because it received fairly consistent good reviews. I used it today and am happy with the results. It's straight forward- apply activator a couple different times, sand, sand, sand, polish and then apply the clarifying compound. If you use this kit, don't be tempted to "touch up" the clarifying compound unless you do it immediately. On the second headlight I think the towel used to apply it got too saturated and I had a run. I didn't smooth it fast enough so the second lens has a bit of streaking but still quite an improvement over how it was before.

I should've taken before pics. They weren't yellowing yet but were getting some cloudiness. Not terrible but figured it would be easier to do them now than wait til they had the look of the windows in a smoker's den. The second pic is the one I tried touching up but as you can see nothing is evident in the pic. The two horizontal lines that run all the way across the lens are part of the lens on the inside. This is on a '06 Tundra.

After pics:
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[Linked Image]