Extended warranties, service contracts, maintenance agreements, etc are sold by leaches who are offering them only because it makes them rich, at your expense. For every lottery winner who "makes out" on their extended warranty, there are hundreds who get no pay back.
Self insure - take the money that you would pay for an extended warranty, put it in a "rainy day" account and use this account only for those items that your extended warranty would have covered. The vast majority of people will end up WAY ahead.
2011 3500HD Duramax/Allison/90 Gal Aux
2015 HD Limited Low