Extended warranties are very good deals for the dealership which makes a large commission and the extended warranty company, who make money by talking in more premiums than paying out claims. The pre approval process is notorious for having a lot of hoops to jump through, any one of which done wrong will result in the claim being denied. And often there will be fine print that if something breaks because a non-covered part breaks, then nothing is covered.
Most people would be money ahead by taking the cost of the extended warranty (which is really a repair service insurance policy), putting it in a savings account and adding to it each month. Then when a repair is needed, you have the funds and don't have to worry about hoops or getting preauthorization. That fund can also be used for replacing things BEFORE they break if you happen to find a worn part that could let go.
Barb