It looks a little bit like a coolant temp sensor. Two wire plug going into it and a brass-like metal piece sticking out of it. Mine was loosely hanging right behind the bumper in the area where the driver's side tow hook cover is.
The other night mine did something kind of strange too. When the temperature dropped below 39*F, the dash chimed and displayed the temperature on the display. I guess it was my car telling me "OMGWTF, turn on the heater!"![]()