UTTG will darken the trim and will last for a long time. I'ts a beauty on trim! I'm not sure how faded the trim is your looking at. If its bad enough I would assume you need PB TR. I'm going to use some PB TR and some UTTG on a severely faded bumper this weekend. I'll let you know how it goes and my findings. I haven't used it on headlights and not sure about that. I use WG Plastik surface sealant for them. A lot of people use whatever paint sealant they are using for paint on the headlights as well.
The trim is actually not too bad. Cars are garaged at night and when not driven. I've used a few dressings that work ok and even the sealants and OCW help. I was just thinking that UTTG might be a better option. I tried to get a sample of the PG TR the last couple of orders but AG has been out. I'd be interested in your feedback, especially since there are cars out there that have faded trim.
I know that Fuzion does not provides good protection for headlights, as the lens started to yellow within weeks. I get better protection from Blitz wax. I use a plastic polish to keep my lens clear but I would love a longer term solution without going to the Urethane+mineral spirit combo when I finally get around to wet sanding them. How long does the WG Plastik surface sealant last for you? Had you considered the UTTG since it holds up so well in other areas?