2009 BMW 650I

BOUGHT CAR FROM DEALER W/18K MILES, TEST DROVE AND NOTICED NOISE/VIBRATION UNDER FEET, STEERING WHEEL SHAKES, (SAID IT WAS THE "SPORT PACKAGE, RAIN, TIRES".) THEY HAD EXCUSE FOR EVERYTHING. THIS IS THE THIRD CAR I HAVE OWNED LIKED THIS AND NO ISSUES OF THIS KIND. FINALLY TOOK TO ANOTHER DEALER, SAID IT WAS THE RIMS BENT, TIRES DAMAGED. RETURNED TO 1ST DEALER FOR REPAIRS TO RIMS/NEW TIRES. THE NOISE SOUNDS LIKE GOING OVER A "ROCKY ROAD" BUT THIS IS CONSTANT & HAPPENS ON ALL ROAD SURFACES. THE VIBRATIONS CAN BE FELT UNDER THE PASSENGER AND NOW THE DRIVER SIDE FLOOR BOARDS. THE STEERING WHEEL SHAKES. THE CAR HAS HAD ALIGNMENTS. THE DEALER SAID THEY REPAIRED THE BENT RIMS, REPLACED THE TIRES. SINCE THEN, I HAVE MYSELF REPLACED THE RIMS, 2 SETS OF TIRES, ALIGNMENT, MULTIPLE BALANCING. I HAVE BEEN AT THE DEALER REPEATEDLY REQUESTING A RESOLUTION. THE RESPONSE IS " UNABLE TO DUPLICATE CUSTOMER COMPLAINT". THIS IS DRIVING ME CRAZY. THE CAR NOW HAS 75K MILES. SURELY, THERE IS A PROBLEM. I HAVE ASKED THEM TO PULL THE WHEEL OFF AND CHECK THE CONTROL ARMS, RACK & PINION, BUSHINGS, SOMETHING IS MAKING THIS CAR SHAKE AND GO THROUGH TIRES. I CANNOT AFFORD $1800 EVERY 6 MONTHS IN TIRES. NOT TO MENTION I HAVE BEEN DEALING WITH THE SHAKING AND VIBRATION SINCE I BOUGHT THE CAR. I HAVE REPLACED THE RIMS AND TIRES. WHAT ELSE CAN I DO? WAIT UNTIL I AM IN A DITCH? THE ORIGINAL TIRES WERE FROM GERMANY, THEN REPLACED WITH CONTINENTAL, I AM ON SECOND SET OF BRIDGESTONE POTENZAS RUN FLAT 19 INCH 245/40/19 ON FRONT, 275/30/19 ON BACK. I STILL HAVE THE ORIGINAL BMW RIMS THAT WERE ON THE CAR, I REPLACED WITH 19 INCH M5 RIMS. THE STEERING MALFUNCTION LIGHT HAS COME ON IN PAST BUT NO CODE. *TR