Sounds like creaking from suspension when I go over bumps, even at low speed manauvering. Car has been sat up alot over covid lockdown. Still realately new at 3.5 years old and 10k Mile's. Very easy life. So would not expect anything to be worn? Perhaps seized or sticky. My wife's subaru makes similar noise when its been sat up for a bit but after driving for a short while seems to clear.
Interesting. Definately sounds like coming from passenger side rear. But also had rear seat folded down then put back up. May fold it back down in case its somd kind of torsional flex of that.