After stripping it down, the harness goes back in the car for actually wiring stuff up. I also cut all the wires off the main factory fuse box and pulled them all into the passenger foot well where I'll make a false floor with a power distribution hub. I just really didn't like mazdas way of powering things. You can already see my 1/0 power wire coming from the trunk and running along the passenger sill. The ground wire is under the car bolted to the trans, and a bare bit of frame.