From the initial test drive, I have felt an unusual vibration felt in both the steering wheel and seat while driving the vehicle. This vibration becomes more pronounced at higher speeds, especially after 70+ MPH, but still noticeable at lower speeds at 45+ MPH. Tires were initially blamed as the underlying cause, and the original tires were completely replaced within the first month of ownership, but the problems continued. Subsequently, at the 2nd month of ownership, the new set of tires were completely replaced again (this is now the 3rd set of tires), and the problem still persists. Dealership tells me that Lincoln engineers are aware of this situation, and that other owners of the 2024 Lincoln Navigators and 2024 Ford Expeditions have complained about this same concerns. Besides the vibration, the ride quality of the vehicle is terrible, and appears to me that the adaptive suspension is not performing as expected. I had a 2022 Lincoln Navigator which did not have any of these issues, and I know how this vehicle should ride and feel, and I know that this particular vehicle is not handling and riding as designed. Vehicle has less than 3000 miles on it and is on its third set of tires, and the underlying issue has not been identified.