[lincpimp]

Unless you live in BFE there should be an automotive fastener shop in your area. These guys sell generic versions of the clip in quantities of 10-25 for 5-10 bucks. I buy from them as I keep a stock of popular clips. Call a few of the body shops in town and they should be able to tell you who they use.

What kind of vehicle is it? I might have some laying around?!

Looks like you have a cardboard style backer on that trim panel. Sometimes the board tears and then you have an issues getting the clips to stay in. I have used hot glue when that happens.

You could also use stainless head trim screws and just screw the panel on. They also make screws that come with snap over decorative caps to hide the screw heads.