bed liner

i want to put bedliner in the back hatch area of my explorer, i removed the carpet and the 4 chain things, but under neath the carpet is this large patch thingy, i dont really know how to describe it, its like a huge sticker, if i try to scrape it off with a putty knife it breaks off kinda like half hardened clay. Shold i continue removing this or should i leave it and put bed liner over it?

 

[schmidlkofer]

is the bedlinner in there thick? and what is the surface like.

 

[sjr033]

I think the bid sticky thing is just the factory sound deadener pad. I would say remove it if is coming off. because if you don't and put bed linner over it, then sooner or later it will come off anyway. removing the bed linner. so chip away, chip away.