I hope thats not your car in your avatar but I cant stop laughing @ the guy in the corner rofl.

Yep it is his.

I have an 04X and believe it has the same hole. Like stated earlier, its meant as an extra air duct to cool the front differential.

He was replying to the post above him...

Hey guys, Just picked up an 05, previous owner didn't have the front license plate cover on it (illegal here in MN, however it was a garage queen). That cover is so you can properly align the Front License Bracket when drilling holes in the bumper to install. Atleast that was what I was told. They did it while I waited.

its for the turbo in the X.

Yeah, it's my car. Senior year in high school, I parked in the very far back thinking I'd be safe. No, hit & run. Never found the dickweed who hit me. Ever since then, I park right in front of the security camera.
But, that was years ago. I repaired it a long time ago.