AS I WAS BACKING UP I APPLIED MY BRAKES AND FOR SOME REASON NOTHING HAPPENED WHICH RESULTED IN MY HITTING MY WIFE'S CAR AND DAMAGING HER DRIVERS SIDE QUARTER PANEL. WHEN I ASKED GMC ABOUT THE ISSUE THEY SAID IT WAS JUST AN ERROR ON MY PART. NOW I FIND OUT THAT THERE IS A RECALL ON THE BRAKING SYSTEM THAT THE PRESSURE TO THE BRAKES MAY BE AFFECTED. WHO IS RESPONSIBLE FOR THE DAMAGE TO HER CAR?