2002 LEXUS LS Suspension Problems

ON 9/6/2007 I HAD A FLAT TIRE. I TOOK IT TO THE TIRE PLACE, I BOUGHT A NEW TIRE THAT THEY INSTALLED. AS I DROVE AWAY I HEARD A CLICKING SOUND AND I WENT BACK TO THE STORE. TWO STUDS WERE BACKED UP A LITTLE AND LOOSENED THE NUTS. ON 11/23/2007 I HAD TO REPLACE TWO TIRES. I TIGHTENED THE STUDS. I DROVE SEVERAL HUNDRED MILES AND THEN ON 11/29/2007 I WAS ON THE FREEWAY AND SUDDENLY THE CAR WAS SHAKING AND HARD TO CONTROL. I REDUCED SPEED AND PULLED ONTO THE SHOULDER. I CALLED FOR A TOW TRUCK AND TOWED THE CAR TO THE LEXUS DEALER. ALL THE NUTS WERE BROKEN ON THE DRIVERS SIDE REAR TIRE. WHEN THE TOW TRUCK DELIVERED THE CAR, THERE WERE THREE NUTS ON THE GROUND FROM MY CAR. THE LEXUS DEALER REPLACED NUTS, SPRINGS, HUB AND BEARING ASSEMBLY, DISC PAD PIN, DISC CYLINDER...