What if the radio in the car is stock, but not the original one that came from the factory with the car. Sometimes people have their cars with their aftermarket decks, and decide to sell the car, but don't want to sell the deck with it, so they buy a used one somewhere (junkyard, ebay, friend, etc.), and put that one into the car. And maybe they overlook getting the code, or giving it to the new owner. And the new owner disconnects the battery sometime, and needs the code?

Its just a thought, but sometimes the VIN# isn't always going to match up with the radio in the car. But as for cutting the key based on the VIN#, thats true! I've seen it myself.