I have a 2007 TL base and noticed that there are 2 sensors on my dash. One is behind the steering wheel, which is a square shape with flat top. The other is on the passenger side, which is round dome shape. I would guess the one on the passenger side is the sensor for the auto headlights, but what is the other sensor?

 

round shaped one is for the Climate control, lets the car know where the sun is

and the square one is for the auto-headlights

 

Thanks! I looked over all the manuals, and nothing was even mentioned about the other sensor.