I WAS DRIVING ON ROUTE 40 (SPEED LIMIT 55MPH, BUT 45 MPH DUE TO CONSTRUCTION) WHEN I BEGAN HEARING RATTLING IN MY REAR PASSENGER SIDE SPEAKER, THEN CRACKLING, A BURNING SMELL AND THEN SMOKE FILLED MY VEHICLE. I BELIEVED MY VEHICLE WAS ON FIRE. HAD I NOT REMAINED CALM, I COULD HAVE CAUSED AN ACCIDENT. I ENDED UP DRIVING TO A NEARBY WALMART PARKING LOT WHERE I LEFT MY VEHICLE UNTIL IT WAS TOWED TO THE DEALERSHIP FOR A DIAGNOSTIC. THE TOW TRUCK DRIVER ALSO CONFIRMED SMELLING THE BURNING UPON STARTING MY VEHICLE TO PULL IT ONTO THE TOW TRUCK. THIS HAPPENED ALTHOUGH NO AUDIO WAS BEING USED IN THE VEHICLE. I GOOGLED THE ISSUE AND LOCATED SIMILAR STORIES ON MBWORLD.ORG FORUM DATING BACK TO 2016. THE ISSUE IS MELTING HARMON KARDON SPEAKERS IN THE 2014 E350 MODEL. SPEAKERS DO NOT MELT AS A PART OF NORMAL WEAR AND TEAR, BUT BECAUSE OF POOR WIRING, ADHESIVE AND/OR CRAFTSMANSHIP. MY SERVICE ADVISOR CALLED ME TODAY AND CONFIRMED MY SUSPICIONS THAT THE REAR PASSENGER SPEAKER HAD IN FACT MELTED AND MY FRONT DRIVER SIDE SPEAKER IS ALSO IN THE PROCESS OF SUFFERING THE SAME FATE. BOTH NEED REPLACING. BECAUSE MY VEHICLE HAS BEEN OUT OF WARRANTY FOR JUST OVER A YEAR, THERE ARE NO RECALLS FOR THIS ISSUE AND IT IS NOT A "KNOWN ISSUE" I AM EXPECTED TO PAY OUT OF POCKET FOR 2 MALFUNCTIONING/ MELTING SPEAKERS CAUSED BY THE MANUFACTURER. THIS IS A SAFETY ISSUE, COULD HAVE CAUSED BOTH AN ELECTRICAL FIRE IN MY VEHICLE (NEAR MY GAS TANK) AND ME TO HAVE GOTTEN IN AN ACCIDENT. PLEASE ISSUE A RECALL BEFORE