Lens sealer after 3M kit

[haimsey]

I've "restored" my headlights with the 3M kit and they look brand new again. However I have been told i need to apply a sealant otherwise they'll just yellow up again in a few months.
What do I need? No idea what I'm looking for TBQH

 

[Andy_con]

apply as much sealer as you want, over time plastic will scratch and yellow up again. they are on the front of the car a take a right battering.

never had this issue with glass head light lens

 

[Krarl]

Ceramic coating. Will take the brunt of the 'scratching' that Andy mentioned too. It won't last forever but it will certainly last more than a year. I did my 172 ones over a year ago now and they still look the same as when I did them

 

[Sunglasses_Ron]

Carpro Dlux

 

[JamesBryan]

Ceramic coating or for even longer lasting, get them lacquered at a paint shop.

 

[hipwell]

Laquer will just chip off and look naff, tried that before.

Just did mine with the meguoars 2 step kit and it came with a spray on sealent, they look awesome.

Claims 12 months on the bottle