I have bought 3 in the last 25 years, 2 on vehicles, and a laptop, Never colleted a dime on the vehicle ones, the laptop / netbook is still active.
I decided I would only get them on high$ new technology that doesn't have a track record yet. I bought one for the Netbook I gave my wife.
It covered the battery, which is over $100, and the warranty was about $80, it also extends the manufacturers warranty for 2 more years. In my experience laptop / portable electronic w / removable batteries usually need a new one in less than 2 years, and since they get carried around they take more abuse .
As far as cars and major appliances - take the money the extended warranty would cost and save it. Also pass on all the extra features on wahser / dryer / dishwasher. They don't make it work much better, and add to the complexity and cost. Simple is reliable.
There are plenty of new vehicles with 60,70, 100K mile warranties, most are powertrain after 3yr /36, so you would likely pay for the repairs on anything not drivetrain related. My bet is the odds are higher of getting in an accident over having the engine / transmission totally blow up if you do the recommended maintenance -which isn't much anymore.
Maybe take the money for an extended warranty and put it aside to cover an increase in collision deductible, and get a lower insurance premium each month.
Just to