They should last quite a long time. But pad life is really hard to say since it really determines on your driving style. Even though you may not drive the car that hard it could still wear out pretty fast. The rear should last a long time because your brake bias is towards the front of the car. I would say your pads should last on average to like 30K. At least that is how long I get out of my pads. I have a friend who still has 80% of his pads left on his car and he has 25K on it. So it is really hard to say.