Paint & Body Work - Body pannel retainer clips?

Anyone know the GM part numbers for the body pannel plastic retainers used on our cars?

I'm in need of quite a few clips that broke during bumper and fender removal. I'm unsure of the exact size of the clips so I would like to get the OEM sizes.

I found this website that sells a bunch and they have a cross reference for the actual part numbers:

http://www.autobodysupplies.com/GMandUniversalClipsPageOne.htm

The bumper retainer clips are the ones under the bumper?

My car had a few missing on the bottom I just found some generic onces and pushed them in till they worked no one had the damn clips I needed. That website helps alot if you can find the ones you need though!