2016 LEXUS LS460 Engine Problems

I PURCHASED LEXUS LS460 AWD 2016 IN 01/2017. FEW MONTHS AGO THE NOISE LEVEL IN THE CABIN BECAME TOO LOUD EVEN TO HEAR THE RADIO. I TOOK THE CAR TO THE LEXUS DEALER WHO SOLD THE CAR TO ME FOR CHECK UP. I ASKED THEM TO USE A DECBEL METER TO READ THE NOISE LEVEL. INSTEAD THEY SENT A TECHNICIAN TO DRIVE THE CAR AND HE SAID THAT THE NOISE WAS COMING FROM TIRES. IF THAT WAS THE CASE I ASKED THEM TO CHANGE ALL THE TIRES (I AGREED TO PAY). BUT THEY REFUSED TO CHANGE FOR SOME FLIMSY REASON TO HELP ME TO SAVE MONEY. I FIGURED OUT THAT TIRES WERE NOT THE CAUSE AND SOMETHING ELSE COULD BE THE REA SON THEY DID NOT WANT TO DISCLOSE OR EXPOSE. IN THE MEANTIME THE CAR STARTED STALLING WHILE DRIVING 2 MONTHS AGO AND I IGNORED IT THINGKING MY NEW...