You wire it like you would any other unit. I've installed two of them and both times I used the same power source and same ground as the HU. As long as you aren't using your HU amp for anything, there is more than enough current for that and the line driver put together. The remote just splices into the remote out from the HU.
4ga is retarded. 12ga is more than enough.
4ga is retarded. 12ga is more than enough.