Hi there,
I found on eBay a bug screen that's hemmed and has eyelets sewn in so it looks neat - can't remember the price I'm afraid, but wasn't outrageous.
To fit it, I popped the bonnet, drilled a couple of small holes in the plastic cowl under the bonnet and used cable ties to secure. I ran the mesh behind the rego plate, and cable tied the bottom edge to the honeycomb mesh in the lower grille in the bumper. Closed the bonnet, so the mesh sits behind the bonnet slots. Comparatively little air on these things goes through the bonnet slots though, so for the purpose I think it really would need to run down to the lower grille as well.
I noticed zero impact on engine temps, including running heavily laden in the NT at 130kph.
It's not the best pic to show it, but hopefully this will give you a bit of an idea...