Haha, it's funny how this thing has everyone wondering!

I doubt it's some sort of traction control...

Can't be the power folding mirror switch, that switch is on the JDM power mirror control button...

Not a JDM Hazard as well, the JDM hazard button is at the same location as USDM. But that's a logical guess. Although it does have a triangle on it. So... :dunno:

The electronic climate control is also at the same location.

Fog light switch is either next to the cruise control switch or sunroof switch (depends on what trim you have).

The rear wiper switch should be on the same lever as the regular wiper.

So I guess that only leaves:
The "parking" antenna switch (which I have no idea what that is).

Or it could be the EDM washer button...
The mysteries... hahah