BH;
On my car that I'm building I have an outside switch (Moroso) that disconnects the battery. Inside I have a toggle switch that controls two big relays; this is my "master shutoff" for the entire electrical system. In the photo it is just to the right of the round button (starter). I have a red cover on it that can be snapped down with a gloved hand in an emergency.
Regards, Neil Tucson, AZ