Best product for resealing headlights after restoration?

[papasmurf]

I finally spent the time to clean the headlights on my car after 100k miles and 20 or so years of being on the road. The lights had 3m protection film on it when I bought it and it lasted another 4-5 years until it was starting to degrade and yellow and I removed it. I have noticed it left a slight yellowing to the lights in places almost like an adhesive but not something you could clean off...just like an etching. After the restoration, that is all finally gone now and they are almost as good as new but I know that the UV inhibitor and protection is gone and would like to put whatever works best back on there to protect them from the elements. I may do the protection film eventually but for now I am looking for whatever UV protection product will work...any products based off experience you would recommend? Thanks.