Join Date: Apr 2019
Location: Middle OH, USA, Earth
Look in the wheel well area for anything that could contact the tyre.
Last weekend, I had the pleasure of hearing a rub in that area too. Turned out to be the little vertical aerodynamic deflector under the body just in front of the wheel well had become dislodged, pushed back by the air flow and rubbed on tyre. It rubbed until it was worn down and pushed to pointing straight back. A new one is on order.
There's a fastener on the inner end that kept it attached to the car. There are two tabs that fit into metal clips, plus a post between them, that go up into the underside. They are at least 1/2 inch long each. One clip was still in the underside and one clip on the outermost tab on the piece.
I was able to turn and position the piece back then push it into place just like it was originally. I have no idea how this happened since there is no sign of physical impact from anything. The length of the tabs and post would seem to make it impossible to come loose.