There is a very irritating noise coming from within or under the driver's seat of my 2017 Volt. It sounds like loose plastic hitting on something nearby. It makes a continuous "clicking" noise on anything but the smoothest road or whenever I shift my position in the seat. It is loud enough that a passenger often asks what is that. I have looked everywhere trying to find the source but have been unable. The dealer just scratches his head and looks like I am being to critical. The car is so quiet, this noise is loud enough to be extremely irritating. Has anyone else experienced this problem or has any suggestions on hot to correct it?