A couple of days ago, I heard a noise emanating from the outside of the car, as opposed to inside the cab area. It is heard at speeds below 5 MPH. So I lowered the windows to hear better, and after some consideration, I concluded that the creaking noise was coming from all 4 wheels; the frequency of the creaking would increase and decrease with the revolutions of the wheels. At higher speeds, the noise was inaudible, possibly owing to other noises like wind and so forth becoming pronounced.
The creaking noise, I discovered, was coming from each of the 4 plastic wheel covers. I removed the wheel covers and the noise disappeared.
Does anyone have an explanation for this? I am confounded.