The trouble with used trunk lids is that the adhesive that bonds the outer skin to the inner structure cracks and falls away. In turn, the lid has a tinny, echo sound when it's shut. i think the reason the repops are heavier is because it has the adhesive there. I took my origial one and seperated the two halves and re-bonded them together. I don't reccommend it, it was a mutha, but it's REALLY nice now! It no longer caves in when pressed on and has a nice thud sound when shut.