The best stuff out there IMHO is CQuartz Finest/UK, and that has a 2 year guarantee, can last longer with proper maintenance. I don't know about 7 years, maybe if your car is garage kept most of the time? I'd read the fine print. For example, how difficult is it to apply, does it work with all types of paints, does it have to fail completely all over the car for the warranty to be valid, are there installers out there, etc. Kinda like Ford's rust protection warranty. Don't count on surface rust to get a warranty claim, it has to be perforation.
As far as bonding molecularly, that's basic chemistry. Everything "bonds" else it wouldn't stick. So ignore that marketing stuff.