Welcome! Sorry to hear about your trouble. We’ve had several threads recently about noise from “down under” (not Australia!) which in those cases has turned out to be worn/fused/sticking U-joints for the rear driveshaft (propellor shaft). The bad news is that Toyota doesn’t list a replacement part for the joints themselves, requiring a new driveshaft at significant cost. In these cases some members who have confirmed that it’s the joints have gotten a replacement shaft from a newer wrecked RAV, rather than a new one. Some have had luck with 3rd party parts. I suggest you have the joints and shaft checked out to see if that might be the issue. Hope you find an affordable solution!
2012 RAV4 Base FWD.
Upgraded to large front brakes and 3rd row rear springs.