How to close this gap?

As I'm prepping my panels for the second round of armor (CF and ceramics went excellently) I'm continually being bothered by something.

How to close the plastic in so that it's one smooth panel? The ridge on the exterior visible in the last pic is especially bothering me. I want these panels perfect before I shoot any paint, and right now they're really bugging me.

I've looked at something as simple as bondoing them, but that would get to be an issue because it would most likely fall out. I thought about putting styrofoam in and then bondoing, or insulation foam (the carveable stuff) but that still leaves the crack around the rim.

Any suggestions? Weight doesn't seem to be a problem, and the panel simply will not flex with a double layer of CF run inside the panel. It's an aesthetic issue, but one that's very high on my list.

What material is the panel? Plastic? If so, I'd look at filling with with the same type of plastic using a solvent weld. You'll have to deal with texture of the surface though. Probably sand it all down and resurface it so it is all the same.

Anyway, that's the best way to do it.

you can do what i did to my car with the bondo. glue a piece of screen in the hole then apply the bondo.