Yes it is using the barrel looking plug to go from the speakers to RCA cables. When i push the gas the noise does not get any louder at all. Yes it is still the factory amp.
I have discovered that when i unplug the front left and right speaker RCA cables from the HU the noise get 10x louder. Im not exactly sure if this tells you anything but it affects the noise.
Also where would the best place to be for the ground to go? Currently they have it screwed into one of the side screws holding the stereo mount.