Heated sideview mirrors?
 

Will the Mazda3 ever get heated sideview mirrors? I noticed that they're not listed on the current 2008 models.

Heated side mirrors are an option on some countries outside the US, however you're correct that they're not offered here. They are however available to add. Your car is wired for heated mirrors up to the harness plug going to the mirror, however there isn't any wiring in the mirror itself (outside of the power for the motor). You have two choices.

The first is to fully replace the existing mirror/housing with a heated mirror that has the wiring. Three bolts, unplug the harness and repeat backwards to install the new one. Viola! Heated mirrors in less than 5 minutes. Those cost about $105/side. The second option is to add only the heated glass and add about 12" of wire to each housing to run from the mirror glass to the plug. That's what I did. If you can do a little soldering and use a wrench then you can do this mod in maybe an hour/side for a total cost of ~$90.

Both of these are using OEM parts, though you can get heated pantoscopic glass on ebay and install it the same way.

Look HERE for my walkthrough.