When I got my hatch from my friend, the radio was installed at Best Buy in Adventura, FL and they passed the speaker wires and door lock wires thru the door panels.
They ran it under the dash and just passed it across the door just under the door panel...so when you open the door you see wires hanging.

I think that is just ghetto because I don't ever remember doing that when i was working at BB or at CC.

I personally use alot of solder and heat shrink to keep things clean.