So here in NC, we don't require front plates, and without a plate up front, the little depression, slot, whatever that the plate is supposed to go in just looks retarded. From pics I've seen it seems there'* supposed to be a filler panel that goes in there if you're not using a front plate, but the car didn't come with it. Am I right here? If so, suppose I just have to go to a dealership and order the part?

Correct. It will be a paint to match item though You may be able to find one through a wrecker to match (or at least closely).

Start a new post in Wanted. Someone here probably will give you one for free.

Problem is GXP'* aren't that common and I'm not sure if the filler panel is the same as in the SSEi.

Ebay. I remember seeing a black GXP filler cover there a while back. You need to look for a 2004 or 2005 GXP cover or 2005 SLE cover. Those are the only filler plates that will fit.

I bought a black filler plate for my SSEi from E-Bay. It was listed at being from a black 05 GXP. It works....

You could just get a custom plate, or one that says Pontiac on it or something like that just to fill the hole.