That stuff does help make a difference if you are in a hurry, but it will wear off unfortunately. I have used it enough to know. There is a different solution. I won't say better because although it is more permanent, it is a bit more work and a little more money(although not bad at all). There is actually a professional kit to put the UV coating bacl on them and it lasts, in this case, typically longer than factory. It does require sanding, but the coating is actually sprayed on similar to a clear coat paint. The difference between this and clear coat however is that it will NOT dry without UV exposure, so it will have to be applied or rolled into sunlight to cure. This cures it to the lense and will not seperate like clear coat can or wear off and dull like polishing/buffing kits will. I have used the following method so often and swear by it. Most can be made to not only look good again, but look like they just came off the assembly line(depending on how fine a grit you use). If you want them to look new again, the depth of chips and scratches determines how you start off. If it is just hazing and few scratches, you can skip the 800 grit. Here it is.

1) tape off the area around the headlights and then cover the front of your car. I just use an old tarp and do the whole thing.
2) Starting with 800 grit sanpaper, sand the lense until it is uniform and there are no longer any deep scratches(note 800 actually puts scratches on hazed lenses, but don't worry)
3) Clean with water and then wet sand with 1200 grit paper
4) Clean with water and wet sand with 1500 grit
5) Clean with water and wet sand with 2000 grit!
Most kits stop at 800 and a few at 1200, but if you look close, you can see scratches left and even created by them. Going further with the grit just makes the finishing easier and better. It doesn't take but a few extra minutes and the sandpaper costs 50 cents or so for a sheet of paper!

After the final sanding of 2000 grit, clean the lenses thouroughly with a mild detergent and rinse VERY WELL with water. This is the most important part of the whole process! Now, with the new lenses clean and dry and sanded to 2000 grit, you should not be able to notice any scratches or blemished. you should just have a dull clear lens that looked great when you were cleaning it, but hazy when it dried.
6) spray the coating lightly over the lenses and put into the sun. repeat a couple of more times every 15 minutes until you are pleased it is covered well. Be sure not to spray it on so thick that is orange peels on you, unless you like that look(It actually looks pretty cool and is so shiny it looks like a factory lense mafe that way if it does happen though) When I got in a hurry and did one like this by mistake, I did the other the same way just because I likes it. I did my crossfires this way on purspose because it looks like an expensive upgraded light. LOL Finally, do not touch it for a couple of hours at least.

Depending on the kit, it will either come in an aeresol can, or just like paint from an auto shop will. If it does not come in an aeresol can, when you are at the paint store, pic up a disposable aeresol sprayer (made for this and minor touch up work for onsite fixes)for 6 bucks and use it. I literally cannot tell the difference in these and replacement lenses when attention is paid to the prep work. This is also a once and done treatment instead of the pastes and polishing kits that have to be constantly redone.

Another option is to call the paint store to see if they have the kits. When they tell you they do, ask them what body shops or detail shops they sell them to. LOL They will usually do all this for you for around 40 bucks, but I kinda think it is fun and I know that the lense was smooth to 2000 grit before it was applied. It makes a difference in how long it lasts, but a good prep guy can make 1500 grit look almost as good, sinced the coating fills in tiny scratches, but I like knowing it is smoother. Long story short, a shiny coated surface sanded with 800 grit looks pretty good from 5 feet away, 1500 grit will make you put your face down there to see imperfections and 2000 grit is undetectible to me at all in any light etc.

BTW, Simply following the above and clear coating them with standard clear coat will last for a long time too(I used to do this before the UV spray film was available), but not as long as the UV curing film. I have done both and both look spectacular. I just don't see the need in doing it again in 2 years or so, so I bought the real deal kit so to speak instead of clear coat. I hope this helps someone else as much as it has me!!! This is a once and done application instead of endless recoatings. It also looks better in the end.

BTW, if anyone else has done this, has anyone tried adding a touch of black pigment to the uv coating? I thought about trying it to smoke out the headlights. I just wasn't certain that it wouldn't affect the curing because it is a bit different than paint, but I doubt it would harm anything. I even thought about lightly airbrushing a flaming x on them with pigmented coatings(like some do for a crossfire logo), but thought that might be a bit over the top and if I got it too dark red, I might get harassed by a bored cop. LOL