Hey guys I am having issues trying to identify this, seems like is not possible to buy this brand new from shops or something. Suggestions are to get it from some junkyard...if I get it from a junkyard, how does this get glued?

I dont even know what is the name of this and I have seen a lot of cars missing it... check attachments

That is the sound proofing/deadening fleece. You can do the same with commercially available sticky back sheets of the sound deadening.

It's held in place with plastic trim clips also called push rivets, no sure of the size , but they are chunky munkeys.