Well.... It may just be by STP. It's been a while since I bought any. Testiment to how well it works.
I tried to search for it on the web but cant seem to find any solid hits.
Anyway, that stuff is something else.
There are two sealed glass vials inside of an applicator that have to be broken and mixed before applying.
One package usually does about 1.5 cars.
I take the vials out, break off the end and mix the stuff in a glass 2oz vial. Then use a small corner off of a paper towel to apply two coates to both of my cars. Still some left over but it precipitates out in about two weeks.

It's up to you all of course but for me, I have used Rain-X in the past and it's really no comparison.