Cropped up in the past few days. I had a rattle from this area months ago(Not the same) and Kia fixed it, now I have this. I took the cover off previously and tried to put in some soundproofing but no joy, but it's right there next to my ear while sat in the passenger seat & it's coming from that spot so I've now put some closed cell foam behind the retainer and bolted it back on & if it still does it I'm just going to leave it off & see if it stops, but I'm wondering if Kia somehow damaged it when they took it off because there it a little grey plastic tab/sound isolator that keeps slipping out when you move the adjuster up/down which clips onto the back of the metal slider.