TDCI plastic underbody panels

[science]

Hi there, I've just bought an 07 TDCI. Seems great so far. However, something I didn't really notice at the dealer was the fact that one of the black plastic panels under the bonnet is missing!

It's the panel that goes right at the front between the bumper and the bottom of the intercooler/radiator.

I'm not sure how vital this panel is, does anyone here have any thoughts on whether I should try and get one fitted? And if so, I guess a Ford dealer would be the only place to try?

I'm also not sure what the purpose of this panel actually is, maybe it improves airflow into the itercooler and radiator, or it might be just a small aerodynamic issue???