I haven't tried the products you mentioned above, but one product I DO use regularly that I know works extremely well is GM Trim Restorer. It may sound funny, General Motors selling trim restorere, but it's definitely true. My cousin gets it from the dealer he works for. He says it was designed to solve a huge expensive problem they were having with the truck/suv model that looks like its made of plastic. The truck that can turn into an suv- i forget the model. Anyway most of the customers were coming back and trying to warranty out all the plastic because it drys out and cracks and looks like A$S. This trim restorer is extremely durable, it makes gray dried out plastic look dark black again, makes it glossy for 3-4 months at a time, and goes on extremely easy. It's not a dye, its actually bluish white in color. A little goes a long way, but the product is expensive as far as i know. I have done a few vehicles with it, and have never had to go back again, but its only been 4 months at most.