The 8 ga power wire feeds directly from the 12v battery thru the driver side firewall and down that side to the trunk. The audio is sourced from the left rear speaker. There is a level knob (more or less sub bass) that I had installed on the drivers seat just ahead of the seat controls (it looks stock). The amp is encased in vented plexiglas and located in the far left trunk (where the mobile charger sits) and is unseen. In retrospect, I could have located the amp under the sub on the other side, but I was worried about ventilation.
I'm an audio engineer and to my ears, it sounds much better than the stock system, but not as smooth as the Studio system. I should have ordered the Studio package! Next time....