I have seen a number of posts here about getting our fenders and other plastics back to being black from that haze greyish colour that they turn. I think I may have found it.
I use the Honda pro-clean on my motorcycle, a Triumph not a Honda. I use it on all aspects of my bike, metal, plastic, seat. I use it to clean the glass in the jeep as well, it leaves a nice shine and cleans very well and decided to try it on a small portion of the fender flare and leave it to bake in the SoCal sun. Well it's still black after two days and I used it on the rest of the plastic as well. You can buy this stuff at any Honda motorcycle shop it's in a spray can. Just my 2 cents.
"I'm the dude, man..., or the duder, his dudeness, El Duderino if you're into the whole brevity thing"