Whats the purpose of the silver plastic piece?

[tb3]

You know... that one piece??? What's it do? just kidding. I'm sure this has been asked a bazillion times, but I'm having no luck with my searches (probably because I don't even know what its called). The little silver plastic trim piece thats right under the front grill (basically touching it almost) that is bolted right to the steel bumper. I know they where on all 84-87 turbobuicks, but I think it was on all 84-87 2 door regals too. Is it purely cosmetic? (Don't see how that can be justified) Or does it have anything to do with radiator cooling? (ram air flow)

thanks in advance for any input!

 

[turbofish38]

It just takes up the gap between the grille and bumper. Purely cosmetic and has nothing to do with the cooling.