This and most other dealer paint/interior treatments are all raw profit for the dealer. As others have said, either DIY or pay a detailer a couple of hundred bucks a year to do it right. Nothing will last forever (or more than 6-9 months for that matter) on your paint. There's no point making the huge investment in this when a $30 bottle of JetSeal, BlackFire, or any other quality sealant will give you the same or better results.
Don't waste your money.