I have a 2021 titanium hybrid that makes that sound. Is yours a hybrid? Mine sounds like it’s in the right rear quarter panel. Ford has looked at it twice, to no avail. It appears to be getting more prevalent now. Also increases sound at higher speeds. Mainly after about 40 mph it starts.I hear a significant flapping and thumping noise that sounds like it comes mostly from the right rear wheel area and to a slightly lesser degree across the entire rear of the vehicle. It is a concussion type of noise and I don’t hear it when the windows are down. It does not record well, but passengers tell me it is more prominent when they are in the back seat area than when in the from seat. It is more noticeable on smooth roads as bumps and rough pavement is loud enough to mask the flapping.
The dealership reported a loose screw on the front was replaced, but the noise did not abate. I have crawled underneath and do not see anything loose, but the material the wheel wells are made of is extremely pliable and is not attached to anything structural on the back side of the tire. The rear bumper is also very flexible and has nothing rigid to attach to on the lower part of the bumper. I can flex and fold these materials easily and when “thumbed” they make a similar flappy type noise as I hear while driving at speeds over 45 and under 65.
Has anyone else noticed this, or is my car just extra special?