Hello, I just have a tour to the cheap Austria sprite behind me and suddenly my L300 gave terrible sounds of itself. They come somewhere from the passenger’s footroom and sound like if you hold a piece of sheet metal or cardboard in the spokes/rotor leaves in a fan or a rotating bicycle tire. The noise is clearly speed and wind dependent. It starts at about 60 kmh and becomes a continuous surrnoise from 90 kmh, really annoying end! I couldn’t find anything that’s loose! Only the number plate has some game in the holder. What else can it be? If it was the license plate, which materials are best suited to make this quiet? PU foam? Silicone gel? ..?