I am experiencing significant and persistent vibrations at highway speeds (60â’75 mph) in my 2024 Kia EV9. Despite multiple dealership visits and repair attempts, the issue remains unresolved. The vibrations cause noticeable discomfort and potential safety risks, especially on long drives. Timeline of Events & Repairs: 1.First Visit to Kia dealer (Dec 24): The dealership performed a tire balance and determined one tire was defective, replacing it. Vibrations persisted. 2.Second Visit (Jan 25) The dealership replaced the remaining 3 tires 3. ThirdVisit (Feb 25): The dealership identified three wheels with lateral runout and replaced them. They also performed road force balancing, reportedly bringing all values below 16. 4.Test Drive (Feb 25): After picking up my vehicle, I drove on the interstate and found the vibrations had worsened, now starting at 60 mph instead of 70 mph. â¢A third-party wheel shop inspected the wheels and found the fourth wheel (not replaced by Kia) was defective and out of round. 5.Dealershipâs Response: Despite these findings, Kia dealer dismissed my concerns and referred me to another dealership for a second opinion. They also stated that third-party evaluations are not accepted, creating an endless loop where I cannot get the issue properly addressed. Safety Concerns: â¢Vibrations impact vehicle stability and driver comfort, especially on long trips. â¢Extended driving with excessive vibrations may lead to fatigue, reduced control, and premature mechanical wear. â¢The fact that multiple components (wheels, tires) have required replacement raises concerns about a potential manufacturing defect affecting Kia EV9 models. Request for Investigation: The dealership has failed to resolve this issue despite multiple repair attempts, and their refusal to acknowledge third-party findings leaves me with no clear resolution path. I request that NHTSA investigate potential defects in the wheels, tires, or drivetrain system of the Kia EV9.