Does the installation kit for the aftermarket headunits work in the lower DIN area or does it looked jerry riged?

The tutorial says that you will need a reverse honda wiring harness for the stock radio and an aftermarket wiring harness. You then connect all 3 wires together (reverse harness, aftermarket harness and aftermarket HU wires).

Now I'll only need to connect these wires to the stock HU: Power, Ground, Ignition, and Dimmer.

thnaks