Personally, if I bought my car new and took good care of it, I would NOT consider an extended warranty. Extended warranties are priced so that, chances are, you will lose in the long run. The companies offering these warranties know this---that's how they make their money!
If your car was bought used and you don't know if it was broken in properly or how it was maintained, or if you have reason to believe that there is a major repair in your near future, then an extended warranty could be worth consideration.