Every car I've owned since my 1999 VW Passat has had one.
They are often present as much to help channel airflow through the radiator as anything else.
Just remember that it's plastic and probably won't survive if you go rock crawling. Other than that, there's really nothing to consider.
I would think the underbody panels are more for overall (underall?) airflow ... laminar, less turbulent if you will.
My only caution is when changing oil/replacing the oil filter ... my dealer likes to leave a little residual inside the panels. Consequently, with so little faith in my dealer, I've fitted a Fumoto valve, and now change it myself.
P.S. Speaking of faith, in response to one of my less favorite comedians, religion is ascription, science is ascription with different words ... I don't see a big difference. Both are trying to explain, to establish cause and effect ;-)