I searched on here but didn't see any results, it doesn't say that this wont work for an RX8 but it looks like it would work. I have an 04 with the bose system.
http://www.pac-audio.com/productDeta...&CategoryID=26

I want to use it with the metra kit and a pioneer double din...

 

Why do you need it if you are getting the Metra Kit?

Doesn't seem necessary when the Metra kit includes everything you need.

In addition to your radio, and the Metra kit you will want a PAC SWI-PS to use the steering wheel controls with your new Pioneer radio. That should be it.

EDIT: It looks like that MAZATO thing is for the CX7/9 and is used as an amp turn on. Since the Bose in the RX-8 uses a regular +12v remote signal for turn on it is most definitely not needed.

 

I was told that with the bose system I need to get something in addition to the metra kit, if not that would be awesome!

 

You shouldn't need anything else besides the Metra kit, and the PAC SWI-PS if you want steering wheel controls.

Where did you hear you needed extra stuff, or more importantly, what did they tell you that you needed?

 

I was told I needed some kind of line out converter, still not sure what that is, but I was looking around for bose/mazda stereo stuff because I had a feeling that it might not work right since I hear Bose can be a PITA to work with. thanks

 

You would only need a LOC if you are adding an amp to the factory stereo. Your aftermarket radio will/should have RCA preamp outputs already.