So I've been using this bottle of Glass Science Glass Scrub for a while and it seems to work VERY WELL. I use it before applying the same company's "Rain Clear" and when used together like this it lasts an INCREDIBLY long time (like, I literally get a year or more between reapplications). Has anybody heard of this? Nothing on Amazon or Autogeek; looks like its been renamed to Glass Renew by the manufacture... Sure would like to know where to source some more when I run out of these two products!