Buying an extended warranty IMO is such a waste of money. Its even more ridiculous when you think that they only sell it for standard miles, ie its not 60K mile factory power train then 100K miles after giving you 160K mile power train warranty. So Ford cars come with a 6 year 60K mile Power Train warranty, if you buy a 100k mile warranty for say 4 grand, you are expecting 1,000 dollars worth of break downs every 10K miles after 60K miles. Sure you can say the warranty is bumper to bumper, so after 36K miles, you are covered for an additional 64K miles. But even then, most cars will not experience 4K dollars worth of break downs before 100k miles.
I get it that some people dont have a couple grand laying around in case their car needs to be fixed, however if you do, a warranty is such a waste of money, chances are you will never use the full value of the warranty. Its like carrying high deductibles on car insurance. I carry 1,000 dollar deductibles, on average it saved me somewhere around 50 bucks a month off my bill. That means after 10 months with no claims, ive already saved the out of pocket deductible difference. Every month after that is just extra money in my pocket. Put that 500 bucks in the bank and collect interest, keep adding till you have 1,000 dollars and boom. You now have your full deductible paid for, earning interest and you have an extra 50 bucks a month in your pocket. I havent made a claim for my auto insurance in almost 10 years now, at 50 bucks a month savings that means ive saved 6,000 dollars.
They sell you a 4,000 dollar warranty for 100K miles because they know the average car wont require 4,000 dollars worth of maintenance. Either you pre-purchase/over purchase repairs on the vehicle or you just repair it as needed.