I have noticed in some pictures that the outside mirrors have a different colored strip through the middle of the plastic casing. Is that a turn signal? Also, are the heated outside mirrors triggered by the defroster or do they sense the outside temperature (like Mercedes Benz)

 

I believe in the very first pictures I saw (like May-July '01), it did appear that there was a row of lights bisecting the rear of the side view mirrors. It doesn't appear to have made it to the production models though.

Also, after reading the owner's manual, it seems that the heated mirrors are controlled by a switch on the HVAC console (HVAC = Heating Ventilation Air Conditioning).

 

That strip you are seeing in some of the pictures lately is just the angle of reflected light.