Hey man, glad to see the trailer brake controller installed... one thing however. Whey you pushed that wire through the firewall around the grommet, it is now sitting against bare metal? It is going to wear through and short out or worse. I used a screwdriver and popped a small hole in that same rubber grommet and ran the wires through there for my Stereo, lights, etc. Rubber seals it from water and protects it from rubbing against the firewall steel.
Will be a quick fix and will save a lot of fuses and no brakes at the worst time! Other than that, thumbs up!