Diamond Luster doesn't ring a bell.
There used to be a Liquid Lustre that was sold at a lot of car shows. Pink liquid, fairly thick consistency. As I remember, it had a great shine, but was a real dust magnet. Probably loaded with oils.
Might be the same product with a new name.
And this link should take you to Liquid Lustre.
I like this site. I don't know what they are selling, but I do like the way they are selling it. I never made it past the first page.