My Civic, battery under hood, drivers side, I ran power down drivers side, tried signal down middle but it was WAY noisy since the car's loom when down the center and split off, I opted to run signal down middle of the pass side, speakers run pass/drivers side, drivers side along with power, XM is also with this. Control for ham radio and mic RJ45 is down the middle to under the driver's seat, coax from that straight across top pass side and meets up with speaker wiring to continue to the rear of the hatch. I had SOME RF issues with the ham rig and switched to a killer coax and that solved it. Everything is pretty much crossed at 90 degree angles.
More than you wanted to know but I figured while the reply box was open, what the hell.
I just ran my RCAs in my E46 and I routed them up to the CD player under the lower center dash part along the right side of the driver's side footwell, down underneath my gas pedal, and from there to my driver's side kick panel and all the way back to the trunk through the wire channel in the door sills. Zip tied to the stock wiring.
It's a tight fit... I made my own RCAs with thick-ass Belden coax cable, which was a huge waste of space... hopefully you have an easier time than me
Battery on passenger side, power and remote turn-on lead on passenger side, speaker cables for right channel on passenger side.
Speaker cables for left channel on driver's side.
All six channels of RCA's and telephone cable (AudioControl Epicenter), run from front of center console under dash, across the floor and under driver seat, across the rear left passenger floor to the driver's side, up along side rear seat on left side.