I was driving to work on the expressway last Friday and all of a sudden the car makes this very loud growling scrapping noise. I'm thinking what the hell is that. The speed, body height handling all seem normal. I begin to slow down and the noise pitch changes with speed. I pull over and the tires are all OK so I look under the car figuring I ran over something I didn't see and its dragging. Well not quite its the bottom aero panel on the IS. I thoough the problem was on the under engine panel. This panel was under passenger side. I went to work and punched out a round piece of 1/4" thick nylon gasket material about 3 1/2 inches in diameter with a 1/4" hole punched off center. This allowed me to use original fastener and resecure the panel for the ride home. The next afternoon I recieve a recall notice from Lexus to have the panel replaced. They describe the failure (noise) and what to expect. Well it took them about an hour and a quarter to replace it with a new heavier panel. Be ready in case it happens to you, I was going about 80 mph when it happened.