Loose part after radiator change. Need ID

[Pfj]

2000 2.3 z3

I was installing a new radiator as the over flow nipple had broken. When putting the passenger side, US, hose on this small part fell to the floor. Can anyone id it?

where does it go.

thanks

 

[Eddie Zedder]

Looks like a headlight vent pipe to me, fits on the back.

 

[Pfj]

You are genius. Thanks. Far left of image.