back struts are bad or exhaust is loose
The noise is possibly the electric fuel pump that is located inside the fuel tank. The tank is located under the vehicle below the rear seat.
Bearings going bad.
Likely a loose or broken strut or shock. Could be the same for a load leveling bar, depending on the vehicle.
You probably need your bearings repacked
could be the CV jopints of the car
it is the universal joint front or rear have someone outside vehicle listen to where its coming from front or back. front of driveshaft or back of driveshaft to rear end.
rear differential got lube? rear wheel bearings?
What kind of noise and is it just one tire?
it could be a bad wheel bearing.
there could be excessive clearance in the rear differential case if this is a rear wheel drive vehicle.
The first thing to check for a wobbly rear end noise is the wheel bearings. If they are ok, check the brake system for worn or broken parts.