I detailed my truck a few months back, after over a year of driving with nothing but handwash and car washes.... horizontal lines, yes...
after polishing, I put down a product from Justin at Obsessive: DR Beasleys Nano Resin, and so far it is an excellent sealant.
The truck looks better (thats a given..) more shine, and washing - dirt and grime washes off noticeably easier.
I'm on mo. 3 and it's supposed to last around 12 months... super easy to apply and remove as well. I was thinking, "that's it?!"
ez sause. you can apply it over graphics, HL's, tails... good stuff.
here's some PIX:
this was after wash/dry/clay bar and wipe down with tar remover....