The AutoGlym kit I’m sure is very good, but it’s worth pointing out that many have used AutoGlym Super Resin Polish to polish out headlamps that are frosted.
It probably depends how far gone they are, but I recently bought a 2009 NC 3.5 and the headlamps were frosted/milky, although not really bad.
I polished them with AutoGlym SRP and in less than 5 minutes both looked like new. Another benefit I would think is that the Polish would provide a protective barrier for some time against UV and road grime ‘damage’.
Might be worth a try first before buying the kit, especially if you have a bottle of AutoGlym SRP already.
If not, it’s worth having anyway as SRP is great for polishing out swirl marks a minor paintwork marks…