THE ELECTRIC REAR DEFROSTER ON MY 2018 F150 XLT CREWCAB PURCHASED IN 10/2018 STOPPED WORKING FOR SOME REASON. I TOOK THE VEHICLE TO THE DEALER FOR REPAIR AND WAS TOLD THAT THE WIRES HAD BECOME DISCONNECTED FROM THE REAR WINDOW GLASS FOR AN UNKNOWN REASON. THE DEALER "REPAIRED" THE DEFROSTER USING EPOXY TO GLUE THE WIRES ONTO THE GLASS AGAIN. THE VEHICLE HAD 13,542 MILES ON IT. I PICKED UP THE VEHICLE FROM THE DEALER ON 1/15/2020 AT ABOUT 7PM. THE NEXT MORNING I DROVE THE VEHICLE TO WORK AT 6AM FOR A 24HR SHIFT. I WORKED UNTIL 6AM ON 1/17/2020 AND WHILE I WAS DRIVING HOME ON A STATE ROAD WITH THE DEFROSTER ON THE ENTIRE REAR WINDOW EXPLODED SUDDENLY WITH SUCH FORCE I THOUGHT SOMEONE HAD SHOT THE VEHICLE. WHILE LOOKING FOR A PLACE TO PULL OVER TO FIND OUT WHAT HAPPENED I SMELLED SOMETHING BURNING. I LOOKED IN THE REAR VIEW MIRROR AND SAW FLAMES COMING UP FROM BEHIND THE REAR SEAT BACK ON THE PASSENGER SIDE AT THE BOTTOM OF THE WINDOW. I PULLED OVER AND CALLED 911. THE VEHICLE BURNED WHILE WAITING FOR THE FD TO RESPOND. THE VEHICLE WAS A TOTAL LOSS.