2015 BMW M235I Unknown Or Other Problems

I WAS DRIVING DOWN THE INTERSTATE AT APPROXIMATELY 70 MPH, WINDOWS UP, SUNSCREEN CLOSED, AND SUNSCREEN SHADE CLOSED AS WELL. I HEAR WHAT CAN ONLY BE DESCRIBED AS A SHOTGUN BLAST ABOVE MY HEAD AND THEN PIECES OF GLASS BOUNCING OFF THE TOP OF MY CAR. THE EXPLOSION WAS EXTREMELY LOUD, OBVIOUSLY STARTLING, AND CAUSED ME TO SWERVE MY CAR AT HIGHWAY SPEEDS. I WAS NOT PASSING UNDER A BRIDGE AND THERE WERE NO CARS IN FRONT OF ME EITHER. I SLOW DOWN AND LOOKED UP THROUGH THE VENTS IN THE SUNSCREEN SHADE AND I NOTICED A GAPING HOLE IN THE GLASS OF MY SUNSCREEN. THERE WAS A CAR BEHIND ME WITH A MAN AND A WOMAN IN THE FRONT SEATS WHO PULLED UP ALONGSIDE ME WITH THEIR WINDOWS DOWN. I ROLL DOWN MY WINDOW AS WELL AND WE BOTH SLOWED TO A SPEED WHERE WE COULD HEAR EACH OTHER....