[Erdem G]

That plug is part of the rear harness but not used in NA cars. No need to worry about its lonely and purposeless existence under the car. 👍🏼

 

[Erdem G]

Some sort of a rear impact sensor, if I remember correctly.

 

[Erdem G]

it's for rear headlight height sensor. if you got one for rear, you should also have one for front sensor in front right wheel arch/engine bay area.

There you go. I remembered it was for some sort of a sensor.