2003 SUBARU LEGACY Tires Problems

I HAVE HAD SEVERAL STUDS BREAK OFF OVER THE YEARS AND HAD TO REPLACE ALL OF THE STUDS ON MY 2003 SUBARU LEGACY LAST SUMMER. THE LAST EVENT OCCURRED LAST SUMMER 2013. BY THE TIME I ARRIVED AT MY 400 MILE DESTINATION, I HAD ONLY ONE STUD HOLDING MY TIRE ON. EITHER THIS IS A HUGE METAL DEFECT WITH THE STUDS OR A POTENTIAL CRIMINAL EVENT AGAINST OUR FAMILY. I HAVE KEPT ALL RECORDS FROM VARIOUS GARAGES WHICH HAVE REPLACED THE STUDS OVER THE YEARS. *TR

TIRE VALVE STEM FAILURE. *TR

2003 SUBARU LEGACY, PURCHASED IN JULY, 2003, WITH FOUR FIRESTONE P20555R16 TIRES (POTENZA RE 92, M+S). LEFT FRONT TIRE BLOW-OUT @ 70 MPH ON INTERSTATE WHILE PASSING A SEMI, WITH VEHICLES BEHIND ON BOTH SIDES. AWD SYSTEM ENABLED ME TO SAFELY MOVE INTO THE RIGHT LANE AND OFF THE ROAD. TIRE FULLY EXPLODED, WITH ONLY RIM LEFT. TOOK CAR TO DEALERSHIP, TIRE UNDER WARRANTY, BUT DEALER WOULD NOT REPLACE UNDER WARRANTY, EVEN THOUGH THE TREAD WAS NOT WORN (22,000 MILES), BASED ON CIRCUMFERENCE MEASUREMENT OF TIRE COMPARED TO SPARE WHICH IS SUPPOSED TO BE THE SAME CIRCUMFERENCE. IN 30 YEARS OF DRIVING, I NEVER EXPERIENCED A TIRE BLOWOUT, AND THIS IS THE FIRST TIME I'VE HAD FIRESTONE TIRES ON A CAR. THE AUTO DEALER INFORMED US, AS WELL, THAT ALL 4 TIRES WOULD NEED TO BE REPLACED DUE TO THE AWD SYSTEM, AND NONE WOULD BE UNDER WARRANTY EVEN THOUGH...