A piller
The part number for the driver's side is 10434739, and cost about $70. Mine got cut while getting a new inspection sticker.
If you go ahead and buy a new one, you can see where the clips are located and know better where to pull to remove the old one.
The molding has a fiberglass backing, and is held in only by clips, but they can be REALLY tight, where you think it will break before it comes out.
When you install the new one, be sure to put some non-hardening body sealer on the clips, so that the holes in the pillar post are sealed. I had a water leak from the factory around one of the holes and it took me a while to track down where it was coming in.





