hdh2r

Was at a red light. Light turned green pressed accelerator then car turned off. Had to take key out and re-insert to turn back on. Radio lights came on but no sound at all in the car. Later that day got back in car and the rear speakers worked but none of the front speakers worked. Another time after turning car on there was no sound whatsoever. Now for days the rear speakers have been working but that is it. Additionally 2 days before this incident I noticed that my Ipod which is wired through a module that basically charges and plays at the same time quit charging but still played through radio. These could be isolated incidents but I would rather get some opinions before my weekend is spent taking the car apart. Keep in mind that Autozone said my voltage regulator in alternator was bad then got a second opinion at a mazda dealership and was told it's good. So if anyone has an idea or has experienced this before please help.

LittleZ360

Almost seems like a loose ground as my first thought.
I'd start from the battery and follow the ground the the chassis. Make sure everything is tight and has good metal on metal contact. Factory grounds on the 8 are kinda lame and could use a little paint removal in some areas... Grounding/Earthing kits help (certainly did for me). Also check the connections between the alternator and battery.
If all that is squared away, I'd pull the alternator and take it in to get load tested.
In the back of my mind I'm thinking some of your stereo/ipod issues may be related to the pressure screw behind the head-unit assembly. My stereo started cutting out at random, and a 1/4 turn out on the screw had ridden the problem for good.
If you still don't make any headway, share your results and findings and i'm sure people will chime in and offer more advice.