2015 AUDI A8 Wheels Problems

I HAVE OWNED MY 2015 AUDI 8L FOR 6 MONTHS AND IT HAS STARTED TO STALL WHENEVER I START THE INITIATION BUTTON. OFTEN TIMES IT WILL JUST SHIFT OFF CAUSING ME TO HAVE TO RESTART IT MULTIPLE TIMES. I BROUGHT THIS ISSUE UP MY LOCAL AUDI DEALERSHIP AND THEY HAVE ACTED AS IF THEY WERE TOTALLY UNAWARE OF THIS ISSUE. ALSO I KEEP GETTING LOW PRESSURE IN MY FROM RIGHT TIRE, THIS KEEPS ME FROM BEING ABLE TO DRIVE LONG DISTANCES AS I AM MILITARY STATIONED IN AN ISOLATED AREA. *TR

CAR VIBRATES AT ALMOST ANY SPEED OTHER THAN IDLE. I HAVE HAD THE CAR BACK TO THE DEALER SEVERAL TIMES. THE VIBRATION CAN BE FELT THROUGH THE STEERING WHEEL, THE SEATS AND ON THE DASHBOARD. I CAN'T GET THE CAR FIXED. I HAVE ASKED AUDI TO REPLACE THE CAR IF THEY CAN'T FIX IT. NO RESPONSE. I HAD 5 AUDI A8'S IN THE PAST AND NEVER EXPERIENCED ANY SUCH PROBLEM I AM ALMOST AFRAID TO DRIVE THE CAR. I LEASED THE CAR FOR 15,000 MILES PER YEAR AND ONLY HAVE 7800 MILES IN 11 MONTHS BECAUSE OF THIS FEAR.

CAR VIBRATES ABOVE 35 MILES PER HOUR. IT ALMOST FEELS LIKE SOMETHING IS ABOUT TO GIVE WAY OR FALL APART. I HAVE OWNED SEVERAL OTHER VEHICLES BY THIS MANUFACTURER AND HAVE NOT EXPERIENCED ANY LIKE IT BEFORE. I FEELS LIKE A BAD WHEEL BALANCING PROBLEM. WHEELS HAVE BEEN REPLACED WITH THOSE OF ANOTHER CAR AND TIRES HAVE BEEN REPLACED BUT TO NO AVAIL.