The light in the pic isn't really an accent light, it's a side marker turn signal. The 1st generation 3's had them (see link below), but for 2010 they were moved to the mirrors. It wouldn't make much sense (to me) to add an additional turn signal (or especially just an accent light) on the front quarter panel.
http://upload.wikimedia.org/wikipedia/commons/8/8c/2007-Mazda3-s-hatchback.jpg
Lol. Why in the heck would you add a side marker light to a car?