Plastic clips: Wheel well.
 

Just looking, and noticed that my front diffuser(?) wasn't flush with the bottom of my bumper on the side. Looked inside my wheel well, and the plastic panel in the wheel well wasn't really attached at the bottom. One or two of the little plastic clips were still left, but the rest aren't there. Checked both sides, and it's mostly the same, the clips are gone.

Which clips are these? Looking through this:
Bumper Cover/Bumper for 2012 Nissan 370Z
For parts, and I can't see any body options that give me the peice of plastic infront of the wheels that I'm looking for. The closest is 10/11 in that link, but the piece attaches to those, and to the bottom plastic cover.

Wheel well - Imgur

You can see the plastic clip that's still there in all 3 pics, but the last one shows that the bottom isn't attached at all any more. Which part is this, and which clips are the ones I need so that I can re-attach this? It's on both sides, and looks to be just clips/bolts needed for re-attaching.

I've got some of those pins/clips. Let me know how many you need and I'll send to you.

Autozone/O'Reileys has those clips for $1 or 2 in various sizes