Have a 2022 Denali, 7 months old, after purchase we noticed if you were sitting in 2nd or third row seat it wobbles. Dealer said tires were out of balance, did rotate and balance and it’s still doing it. Dealer again says sounds like needs to be balanced, so I tell him we’ve tried that already, wants me to pay for balancing again. I refuse to pay as they’ve already tried this, anyone else having issues with wobble. The rear seats literally shake at speeds above 35/40.