All I know is that when I leased my previous car, the dealer insisted that I have the annual paint protection applied free of charge each year, and even gave me a cash incentive at the end of the lease if I did so. They said that it makes a big difference in resale value when they have to turnaround the leased vehicle four years later. I have to admit, the paint job looked showroom new after those four years.
I bought the paint protection for my XFire and almost a year later, it looks as good as ever with just a wash. No, it's not as slick as that glass look you get with Zaino, but it's as good as any on the showroom floor.