I've only had this lying around for ~2 years (as of the upload date), so I figured it was about time to install it. I used two 6ga power wires soldered directly into the battery terminal going through a 150A fuse & a single 4ga ground to a factory hole in a double-layer section of the body which was sanded to remove the paint & through-bolted behind the carpet. The 9-foot 14ga 3-wire extension cord runs behind & under the back seat & hangs out on the hump so anyone can access it.
I think the inverter was ~$100 at Costco back then, but they've updated it to a smaller version that was selling for ~$40.