Driverside Front lowerfender,(Small opening)

Does anyone what the small opening is on the diverside front lower fender. Looks like a small triangle with a small round plastic rod in the middle !

I would say it some sort of sensor, but don't know what it's sensing.

That was my toughts also. Nothing in the manual or anything that I could find online. Maybe for the outside Temp.

That's the outside air temperature sensor. The matching grill on the passenger side is open on the 35i to provide airflow to the oil cooler.

I guess you could get someone to hold an ice cube on it while you watched the temp display on the dash.