The best cleaning/detailing products seem to mostly be silicone-based. I found on my motorcycles that spend a lot of time outside subjected to UV rays and heat fade, in addition to over-wax, that straight-up silicone really does the trick. I use a bottle of DOT 5 brake fluid. this is DIFFERENT from DOT 5.1, which will eat paint, and it is different from DOT 4 or 3/4 or 3, which will eat paint. DOT 5 is synthetic, it WILL NOT eat paint, and it lasts longer than any other back-to-black product I've tried. I apply it with a cotton gardening glove, just get it all on there and rub it into the surface. Sometimes a normal old toothbrush or Q-tip gets it into the cracks. Rub it in, wipe off the excess, and see a rich lustrous long-lasting black in your plastic or black-painted parts that lasts many washes. This stuff brings the trim in the windows and windshield, the bumpers, the mirror mounts, and all black interior parts back to great shape. And since it's straight-up silicone, it doesn't dry them out or cause cracking. Nor does it hurt if you get a smear or drip on the painted parts.
Well worth a try for our older Rangers out there.