Question:
What do you do when you have some leftover coroplast, some spare time, and a gaping air hole in the front of you're truck?
You make a grille block of course
Here's the grille
A few minutes of cutting later.....
And the finished product...
I'm pretty sure that the lower opening will be more than sufficient to provide airflow unless I tow something. If needs be I cut a few zipties and I have full airflow back immediately.