Help with custom install

[BMRbrnSNRbrd]

So here's what I'm doing to the lower bumper area:



Here's the progress I've made so far:

Lower bumper opening without insert:


Cut out the vertical supports:


This is just to show how much of the space the bar will fill. The bar is just sitting on the lower bumper:



As you can kind of see here, the lower insert not only curves up but curves in as well:



My issue here is that, obviously, the bar does not curve in any way. So here is the only option I can come up with. I would cut along the red line you see here:


Now, I could either leave it wide open and the bar would just sit back a bit in the center OR I could fill this area with some sort of black mesh. I like the mesh idea, but then again I don't because the upper grill is not a mesh.

Thoughts?