 I was  surprised to hear a grinding noise from rear at about 2 years and a few months after ownership. I'm not an aggressive driver who is constantly accelerating and braking, i maintain constant speeds with very minimum soft braking. my fears were confirmed when the dealer confirmed that my rear brake pads and rotor has to be replaced at ~ 34K miles and these things are not covered under warranty. just do a simple internet search on mazda cx 5 and brake problem you will receive many many hits. complained to mazda usa and nhtsa. my nissan rear brakes lasted for about 5 plus years approx 65K miles before they were replaced. this suggests something wrong with mazda cx 5. another issue im facing with this car is squeaky seats , they started after the first year.. it is very annoying.. all seats squeak, so suggests some bad quality material and design...another issue is some constant rattling noise from rear side... dealer is not willing to look into this in much detail. he wants me to leave the car at shop for few days before he can get to it... just living on with this annoying noise...Update 06/2016Mazda agreed to cover parts cost for brakes replacement this time, but dreading more frequent replacements in future..  The squeaky seats and rattling noise have not aggravated so okay for now.. Almost Hitting 45k miles .. Everything else is good go