REAR BRAKES FAILED TO PROPERLY FUNCTION WHILE THE VEHICLE WAS IN FORWARD MOTION ON A HIGHWAY. BOTH REAR BRAKES LOCKED UP WITHOUT OPERATOR PRESSING ON BRAKE PETAL. BOTH REAR BRAKES AND WHEEL GOT RED HOT CAUSING PASSENGER SIDE REAR BRAKES CAUGHT ON FIRE. NO BRAKE WARNING LIGHTS WAS ACTIVATE. THIS EVENT TOOK PLACE TWICE, ONCE ON 1/27/16 (18 DAYS AFTER PURCHASE) AND 2ND TIME 3/7/16. (30 DAYS AFTER IT WAS ALLEGEDLY REPAIRED.