Every year or so, the rear brake rotors on the vehicle require replacement. If they aren't replaced, the vehicle will vibrate heavily when braking, which is an indication of a warped rotor. Not sure how rotors get warped within a year of being replaced every single time, must be a caliper issue. Don't really want to pay thousands of dollars for new calipers though, would rather just deal with the vibration every year. This is significantly annoying, but NOT a safety issue.