To my knowledge the only way to properly fix it permanently is to re prep and re spray the entire panel. That being said I have seen some videos on YT of...
Tell your friend to look at theretrofitsource.com for headlight/lighting upgrades or lightwerkz.com. Both supply quality LED and HID components and have some drop in stuff for jeeps.
You should look into the collinite No. 915 its there high carnuba show wax, I believe it provides the most gloss of all there waxes/sealants. I have used it on my black vehicles with great...
I daresay armor all spray on, goes on like a water based (Im assuming it is) intense shine for first day then fades to a nice black for about a week. Not the most durable but its like $5 for 30oz...
This build up you speak of, wouldn't it be layers of protection building up? Or is there a negative build up? I inquire because I use Aquawax as a drying aid myself and have been.
I've used the meguiars re-freshers before, I like the new car scent and thought they lasted longer than most standard air fresheners. Meguiars Air Re-Fresher Odor Eliminator