I bought the extended warranty on the last 3 cars I owned. As with many others here, I never needed to use it but it was the sense of security that made me decide to purchase it.
Here in Vancouver, if you buy the 6 yr / 160,000 Kms extended warranty for $1349 Cdn, you get "Club Zoom" card that allows you the free oil and filter with every oil change for the 6 years. Its worth about $30 because you will pay $20 for the labour only. Mazda's maintenance schedule indicates oil changes at every 8,000 Kms. So 160,000 divided by 8,000 is 20 oil changes, which equals $600 worth of free oil and filters (assuming you will do the service at Mazda, which I was planning to). If you look at it this way, the extended warranty only costs you $749 Cdn before tax. You also get the roadside assistance in USA/Canada for 6 years so if you are a member of AAA/BCAA, you can cancel that membership and save $36/$60 there.