Help identify part and mounting

So I was trying to track down what seems to be an inverter loop leak of coolant, and while doing so, I found this part that seemed to be just sitting in the cavity in front of the radiator on its side. The reason I think it was on its side is because, A: it was loose, and B: it appears to have a smooth notch in it where the latch lever would make sense to protect fingers. Extra points if someone can get a picture of it mounted to accompany a verbal description of its orientation and mounting position.

 

Oh, duh. Sorry. Is a 2017.

also I experienced white smoke today so had it towed to a mechanic. I’m afraid it was leaking into a cylinder. Perhaps oil I guess. It wasn’t missing at all that I could feel.

 

To respond to everyone.
75k miles.
That plastic part's number: 16562-37010
White smoke caused me to take to mechanic, as mentioned, they identified the coolant leaking into the catalytic, as mentioned by Kithmo (I think that's what you referred to).
Quoted $2k to replace, very little in labor. Seems the cat theft causes prices to be wild.

Knowing it's not the motor leaking somewhere is a great comfort, but I'm struggling to find an affordable cat. I'd be happy to install it myself since it's all bolt on, but even the mechanic was only quoting an hour or two for install anyway. So probably easier to go that route.
Is my only real option to buy a new cat?

Thank you all!

 

I haven’t contacted the dealer yet because I expected theirs would be highest of all. Assuming I’ve been seeing the correct part across sites, new seems to have a range of about $1600-2200.