Well, in my experience, nobody wants the warranty more than the guy who turned it down, and now needs a $7000 transmission or a new engine. We sell OEM warranty here from the manufacturer, and no matter what you tell some people, they assume it is a massive scam of some sort, while it's essentially the exact same thing.
I have had this exact conversation in our dealership:
Customer: "My engine needs replacement, it's $8500 what are you going to do to help?"
Me: "How many kilometers on the car?"
Customer: "130,0000 kms."
Me: "Let me check our records <pulls file and comes back 10 minutes later>. It looks like you were offered a 10 year 200k warranty, but signed the waiver and declined it, I'm sorry, the mileage will be too far out to get you an exception."
Customer: "If I knew this was going to happen I would have bought it. This is BS, expletive, expletive, expletive. You fataing suck at your fataing job. Fata you!"
You're damned if you do, damned if you don't. You try and sell it, and you're too pushy, you're not pushy enough, and you are somehow responsible for someone rolling the dice and getting stung. I don't get satisfaction one bit out of it, because now you've lost a customer. But one thing I always did, is keep redacted copies of some major big ticket repairs we have done under the extension, and use those in an evidence manual.