I have a 2016 P90DL. I recently had a new rattle come up that was driving me nuts. It sounded like a piece of plastic vibrating at a high pitch, anything over 60mph would make it consistent, and loud. In my trunk, I found a piece of plastic (not sure what it is for), but taped it over this morning. Noise is gone. I'll probably replace the masking tape with felt, or vinyl for aesthetics. Hope this helps someone else!