Anyone had Black trim fade when using good protecant for a while?

Good question. I wonder if it would look better or worse if you hadn't used protectant or used a different one?

I've had nothing but excellent results with 303, but don't doubt what you are saying. Graying can be a build up of protectants, waxes, crud, whatever. Or it can be oxidation of the plastic.

Try this. Clean the trim thoroughly with dawn hand dishwashing soap diluted like when it is used to strip wax off of cars. Then apply trim protectant. One of the protectants that claims to restore black might be better. They tend to be thicker and might bridge the irregularities in an oxidised surface better.

 

I have been using this stuff since the week I bought the car. Never saw it in autoparts stores although I am quoting a local parts store link but I got it at the Toyota Parts counter. None of my plastic has faded and I found its the only thing that works on that strange plastic around the MFD.
Lots of people recemmend the 303 so it must be pretty good. I have never run across it or I would try it.


Advance Auto Parts: Back-To-Black Trim Restorer by Mothers - Part 06108___

 

A lot of Spa and Boat supply places carry it.
You can do a search for a local retailer here
303 Products - Aerospace Protectant, High Tech Fabric Guard -  World's Leading Automotive Care Products
since you are on the water, you should have a few places to choose from.

 

It also depends a lot on the quality of the plastic trim. IMHO, the trim on the Gen II Prius is pretty low quality, and mine is faded also after years of protecting it...and I always used a gel tire dressing type product.

 

On old motorcycle parts, I've had good luck with Back to Black for regular use/upkeep but for significant fading or worse, graying out, I've found petroleum jelly works best. It needs to soak in; preferably overnight and not in direct sunlight then wipe off and lots of rubbing out.