The lexus dealer actually did a lot of work to resolve the vibration, they changed both tie rods, both the ball joints, both control arms, drive shaft flange anhd finally the rear differential. All this repair on a 99 GS400 with 76000 should las for a while. The tech actually proved that the tires were actually moving on the rim and he says its really common. He marked the wheel and tires then we take it for a ride when we came back and put the car up on the lift 3 out of the 4 tires moved by at least an inch I saw this myself. he then dismounted the tires and clean the rims, after cleaning the wheels he put on a sort of sticky paste around the wheel then remounted the tires. After the remount and balance the car ran smoothe from 10 - 100 MPH.