Is there any kind of replacement piece for it. The stock one kinda sags a little, I have tried to straighten it out but it goes back to sagging. Its only a 1"-2" of sag, but its just something I find to be annoying.

 

are you talking about the little cover that goes in the hatch area? the one that snaps on the headrests?

 

mine sags, but i have the seats reclined to.. if u straighten out the rear seats they wont sag...

 

ditto...

 

Mine sags, but the seats aren't reclined. I've taken it out and it's genuinely warped because there is no support underneath and the material is pretty flimsy.

I'm sure you could probably go to your dealer and order a new one. The sag doesn't bother me that much for now.