I decided to look for a forum after this experience with my 2017 Leaf. I was hearing this thumping noise that sounded like the right rear tire was flat or the fender was flapping. Didn’t see anything when I looked. It started again when I reached 30 mph. I looked backwards and saw my back right window was all the way down. It stopped when I put it up. Anyone else experience this? Is it a design flaw?