2010 LEXUS LS460L Structurebody Problems

ON 08/27/2018 AT 11:30 A.M. I WAS DRIVING ON THE EXTENDED ON-RAMP TO ROUTE 288 IN CHESTERFIELD COUNTY, VA AT ABOUT 55 MPH. IT WAS SUNNY, NOT HUMID AND THE TEMPERATURE WAS IN THE HIGH 70'S; THE ROADWAY WAS SMOOTH AND CLEAR OF OBSTRUCTIONS. MY A/C WAS ON, THE WINDOWS WERE UP AND MY MOONROOF WAS CLOSED AND THE SHADE PROTECTOR WAS SHUT. THERE WERE NO VEHICLES IN MY SIGHT IN ANY DIRECTION. ALL OF A SUDDEN, I HEARD A VERY LOUD NOISE, LIKE A SHOTGUN GOING OFF IN A CLOSED ROOM, AND IN MY REAR VIEW MIRROR I SAW DEBRIS COMING FROM MY VEHICLE AND LANDING ON THE ROADWAY BEHIND ME. THINKING THAT SOMETHING HAD COME FROM THE BOTTOM OF MY CAR, I PULLED OVER AND EXAMINED THE REAR AND UNDERNEATH OF MY VEHICLE. FINDING NOTHING AMISS, I WAS SURPRISED, BUT WAS EVEN MORE SURPRISED WHEN WALKING BACK TO...