Behind both of the front door panels, there is a plug that seemingly doesn't have any function - at least none that I could think of. Maybe someone will know what their role is...

This is the plug:

 

...and this is the socket it plugs into. Now, my car has the sport package only - is this something that's only used in the touring or GT package? For instance, the plug for heated mirrors, and the socket is just to keep it in place? Doesn't seem likely, but who knows...

 

Could it be a sensor, not just a socket. Looks pretty beefy to be just a "place holder"

 

Is there a light on the bottom of your side mirror? If you don't then I'm pretty sure that socket is for that purpose.

 

Can you post a pic that shows this plug area up close, then one way back showing whole door? Might help to figure it out.

 

Well, here is a close-up picture of the "socket"... as for the plug, I have no better close-up shot of that, and the door panel is already back on so I can't take any more photos. But the "socket" doesn't look like a sensor... it's just sitting on the backside of the door trim panel and I can't see anything that would use it. The opening you can see next to it is the oval shaped hole for the door opener handle.

 

And here is a shot of the whole door, with the plug marked with red:

 

Oh, and I don't have a light on the bottom of the mirror. The US cars don't have that, unfortunately

 

Looks like it's the power connector for the light that illuminates the window and mirror control switches.

 

Use a multi-meter and test it. It looks like it has a orange wire. And on some cars orange was used to inidicate illumination when the parking lights were turned on.

 

What packages come with heated mirrors? Could it be a power lead for that?

 

Maybe it is the shock or activation sensor for the side curtain airbags. I would watch putting anything in there for fear of setting those things off.

 

Tamas,

I saw the same thing when i took my doors apart too. I looked through the electrical connections and didn't see this. But then again, it's all spread out in the manual. It would be nice if they did a section (like the door panel) and listed each page that the harness shows up on IMO.

At first when I saw these I thought it might be the sound sensor for the head unit. As far as I can tell, these are exposed when the door panel is put back on. They are just above the door "handle" I beleive. At least that's what I noticed. But the mike for the head unit is about opposite in the dash to the one button start. So that's not it. Perhpase the temp sensors for the auto climate? Assuming that there are settings for the driver and passenger. (Doesn't that form a warm front between the two occupants? ) Of course those would not be used here in the states.

That's just a guess, but I plan on looking again when I have more time ...