I picked up a 2013 GS in March from a dealer in SC.
When the car was delivered to Williamsburg, I didn't notice a wire coming out of the mirror.
It looks like the old telephone cable plug with clear wire.
Any ideas?

 

XM antenna in the right door mirror?

 

It's a radar detector power supply.

 

I installed the same.

 

Is it powered on all the time or is it accessory switched power?

 

Have mine connected so that it is off when the car is off. I can’t remember if there is an always hot terminal choice.

 

I need to check if it is accessory operated.
I would like to use it for my dash camera.