Line-In Solution
I have a new 05 Mazda 3 on the way in Sept, and had hoped it would have a line-in or a AUX connection in the stereo so that I could plug in my MP3 player. I had hoped, because so many 3 buyers are on the younger side and younger people are generally more tech savvy, that Mazda would see the value in adding a MP3 player line-in right away (and because Nissan offers this in the Sentra). This didn't happen and it doesn't sound like the 05's have this feature either. So I have been looking for a way around this problem.
FM modulators were invented for this exact reason. However they require a power source and don't have the best sound quality (ground loop issues, etc.). Anyways after some more digging I was able to find a solution:
http://www.mazda3forums.com/viewtopic.php?t=8831
This PIE solution uses to components:
1- MAZ/PC-ALP (
http://www.discountcarstereo.com/detail.aspx?ID=445 ): This device is a protocol convertor (originally designed to allow you to hook a Alpine CD changer up to the stock Mazda radio) and connects to the back of the radio and "translates" the electronic signals from the "language" of the mazda radio to the "language" of Alpine. It gives you an m-bus connection with the Alpine "language".
2- ALP/M-RCA (
http://www.discountcarstereo.com/detail.aspx?ID=124 ): This attaches to the m-bus connection above and gives you standard RCA input jacks.
All you have to do is get these 2 components and hook them up to the stock radio and then hook in your iPod (or any other music player, laptop, DVD player) and hit the CD button twice and then you have sound. Lots of people have had luck with this solution. Only problem seems to be if your car has a NAV screen (not going to be much of a problem for Canadians).
According to what I have found this will work for the 3, RX8, 03-04 Protg, 03-04 Tribute, 03-04 Miata, 02-04 MPV, 03-04 B-Series. I'm assuming that it will work for all these models in the 05's unless Mazda makes big changes to the radio.