What is this and how do I secure it?

ReeceZ

Hi guys,

Been getting this annoying sound from the trunk when going over bumps. I would use the search, but I don't know what it's called. I put some tissue in the recess when the trunk lid closes, seems to have helped. Weird thing is, when I put the top down. That sound stops and I start getting something that sounds like its rubbing together; sounds like a squeak or even a chirp. Anyway, here's the pic, hoping someone can tell me how to secure this and get rid of that other sound as well. Thanks