I have my 2 front speakers in parallel going into 1 channel (basically the red aux) and then the two rear in parallel into the other (white). I did this so that I could control the gain on each channel so that I could balance the volume form front to the back. I have a second amp for my sub.
The reason why I didn't go 4 channel is because I only ran 2 aux sets out of my HeadUnit; one for the components and one for the sub. It was just easier that way and I didn't need to be able to control each speaker at each corner individually.
Here is a pic of the area I'm talking about. It's not my car nor setup but it shows the location.
WTB: 370z Trunk Foam
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