Thanks to all. My son decided to just buy a new one, and not worry about previous history.

That's what my girlfriend's parents did back when they got her 2021 CX-5. We looked at used CX-5s but they all had some kind of issue or quirk. We test drove a used one at a Mazda dealer that smelled like fish and when got back to the dealer, the front brakes were smoking like they do in Nascar when overheating lmao. I was trying to get them to go certified pre-owned since you get the extended warranty and don't take on the original depreciation loss, but the new car has been great with no complaints other than a couple of warranty work related things.