Unless you are getting a true "extended warranty" from the factory you bought it from, that's one thing... If it's just a warranty from some 3rd party vendor, then you better read the fine print of what is covered and what is not and what hoops you have to do to make a claim..
Most have a "pre approved" before you have any work done.. What does that mean.. Say you are on the road, break down. Need to get a repair done so you can get back home. You get that work done. Then try to submit it to your "warranty" company..... "Sorry, we can't cover that because you did not get prior approval for the work done..." Or something to that effect..
Nothing wrong with getting these kind of "warranties"... Just make sure you understand all the fine print and follow THEIR RULES...
For me, I'd just save the money you would have spent on the premium and self insure myself.. Same bet in the end..
Good luck!
Mitch