I used back to black on my other car.... lasted a few days then turned grey again.
I recently purchased "refinish restorer" from a company called Ditcheck and Sons who run a yahoo based web store. My "Next Day Air" delivery took 9 days, several emails, and a couple phone calls. Granted, they refunded my expidited shipping fee, (which was more than the product itself). But 9 days later I received the product. It looked like it was drop shipped from Illinois, so dont count on Ditcheck to actually have product in stock, they drop ship from whereever they can find the product, which appears to be manufactured in the EU.
I know there are tons of reviews on using this stuff, so I'll add my quick 2 cents.
First application, I prolly used too much, and it looked "streaky". I let it penetrate for 30 mins or so and applied a nother very light coat. I was very pleased with that at the time, but the next morning, it REALLY shined up great. Took about an hour and a half to get decent coverage on those first two passes with it to get the streaks out. Guess it takes longer to realy sink into into the poly properly, what kinda wax may have been on it etc. Might also depend on the condition of the poly to begin with.
I ran into some rain and minor puddles today, and that had no effect whatsover, the stuff just shrugged it off.
Worried about lint, I used the finest microfiber cloths I had. That was a mistake because the cloths are ruined, that stuff simply wont come out of a cloth in a wash. Today, I noticed a few barely noticable streaks and a blotch or two so I went at it again VERY lightly doing the entire cladding again this time with a cheap red shop type cloth you find at walmart. Apllication time was less than five minutes, and the whole process was much easier. No obvioius streaking or blotching. This time it just soaked right in,and looks fantastic. I suspect tomorrow it will look even better.
Back to Black has nothing on this stuff.... sure, it will shine up in 5 mins, but will shine off in a day or two.
Given the performance characteristics of restorer, I expect it to last a month or more after I finally got it applied to my satisfaction.