The arrow points the terminal where reverse lights are wired. A red/black wire goes from this terminal to the reverse light switch on top of the gearbox.
A thick extension for the battery positive. Also, makes things easier when there is just single wire going to the battery terminal
Also, I decided to use the stock intercooler mounting points as new body grounding. The picture is missing a wire that goes between the two mounting points.
The red wire on the the second mounting point is also for grounding. I taped it black bit later to keep red wires positive and black wires as ground.