Hummer H2 trim part

[EricH3]

If you fold down the rear right-side passenger seat back this will expose the black metal hardware which attaches the fold-down center console to the left-side rear passenger seat back. As you raise and lower the center console (and cupholders), you will see how the metal hardware "pivots" -- the plastic part in your picture attaches to that metal hardware. The two "nibs" protruding out of the plastic trim piece simply snaps into the pre-fabricated holes in the metal hardware. If one of those "nibs" is broken or worn (like mine is), then it's just a matter of time before the trim piece will eventually fall back off. One solution is to attach double-sided 3M tape to the back of the trim piece when reattaching it to the metal hardware, thereby making it much harder to come back off on its own.

It acts as both a covering and protection so that it doesn't tear the other seatback, and helps prevent passengers from getting pinched by the hardware or snagging their clothes, etc.