Rattle from dashboard when car hits a bump in road
Have you talked to the dealer about this? You could take the service advisor out for a ride and show him if you know of a spot this occurs near their shop. If they tell you all the 2020 Santa Fe’s do this, take another for a test ride to a big bump and see if both SUVs rattle. That’s assuming this qualifies as warranty work. I don’t know if that’s the case or not.