TSB: SUNROOF BUZZING NOISE - THIS BULLETIN PROVIDES INFORMATION ON SOME 2016MY OPTIMA (JFA) VEHICLES, PRODUCED FROM SEPTEMBER 28, 2015 TO JUNE 20, 2016, WHICH MAY EXHIBIT A BUZZING NOISE THAT MAY INCREASE WITH INTENSITY IN CONJUNCTION WITH THE HVAC FAN SPEED. THIS CONCERN IS CAUSED BY A LOOSE SUNROOF WEATHER STRIP VIBRATION DUE TO AIR LEAKAGE PAST THE SUNROOF SEAL. TO CORRECT THIS CONCERN, FOLLOW THE PROCEDURE OUTLINED IN THIS BULLETIN TO APPLY ADHESIVE TO THE WEATHER STRIP BASE.