TL* THE CONTACT OWNS A 2011 GMC TERRAIN. THE CONTACT STATED THAT THE VEHICLE WOULD VIBRATE EXCESSIVELY WHEN BEING DRIVEN OVER 30 MPH WITH BOTH REAR WINDOWS OPENED. THE CONTACT STATED THAT THE VIBRATION WAS SO SEVERE, THAT IT WOULD CAUSE HEADACHES FOR THOSE RIDING IN THE VEHICLE. THE CONTACT TOOK THE VEHICLE TO THE DEALER WHO ADVISED THAT THERE WAS A DESIGN FLAW WITHIN THE VEHICLE THAT WAS CAUSING ABNORMAL WIND PRESSURE AND VIBRATIONS. THE DEALER STATED THAT THERE WAS NOT A REPAIR AVAILABLE THAT WOULD REMEDY THE FAILURE. THE VEHICLE WAS NOT REPAIRED. THE FAILURE MILEAGE WAS 6,000.