Here was an idea
the factory blocked the side bottom grills by default, by swapping some things that look like a grill, but is actually just nothing...
I could block the sides on the bottom, and partially block the center bottom, but not significantly block center bottom
The original front entrance is 23 inches, I could block maybe 4 inches on each side on bottom, leaving 15 inch wide gap?
I'd fully block top.
Hows that look?
I hope you like my crappy drawing