Hi there,
Sorry if this has already been discussed but I'm such a newbie at this audio stuff that I wouldn't know it if it reached out through the screen and poked me in the eye. TT I'm trying to learn tho!

So basically I'm looking for some kind of adaptor to interface between my stock (base) headunit and the wiring harness because I'd rather not cut any wiring when I hook up a 4 channel amp through a LOC. This way, I could hack away at this "placeholder" and always remove it later when I revert back to stock. Does such a thing exist? where can I find one?

Thanks in advance!

 

I have seen harnesses like this before, but certainly not for the RX8. However you could easily just you the Metra 70 and 71 series harness to make one yourself.
Metra 70-7903
Metra 71-7903

One male end plugs into your stock non-bose radio and the female end plugs into your existing wiring harness. Then just solder the leads you're not tapping together (+12 constant, +12 ignition, etc). Use the speaker leads as you need em. When you're ready to remove your custom additions, just unclip and return to stock.