I have an 02 ranger and the door window trim has speckled, i think due to the high sulfur content in the sprinkler water around here. it was like that when i bought the truck. Is there a way to fix this, or a chrome/black vinyl i can apply over it so as to cover it up. it makes the truck look older than it is. I tried mothers back to black, but it didn't work well.

 

I'm not sure if it will work for that specific issue or not, but you can try a can of Pledge.
I use this for exterior trim and the reason I'm recommending this is because I also tried that same Mother's product on my wiper cowl and my wife's window trim on her Expy and it didn't do anyhthing; although I did not have the same problem as you (just weathered).

I saw immediate results with the Pledge.

 

Hate to admit it, but my brother is has been a GM parts salesman for as long as I can remember. He recently gave us a 2 bottle kit for restoring all the black on our F250. He said GM came out with it because of all the problems they had with the Avalanche plastic fading.

Gotta admit, this stuff works. The All Purpose Cleaner not only worked on all the plastic & rubber parts, but is the best "bug" cleaner we've ever tried. The polish (or whatever its called) is way better than Back to Black. The Back to Black didn't do squat to the weathering we had on our truck.

From what I was told by my bro, you can't get this stuff at all Chevy dealerships so you need to press the parts guy to call around. I think the 2 bottle kit is like $35. (family discount price). You may have to lie to the parts dealer and tell them that you have a Chevy, but it sure was worth it.