Battery Shut Off Switch

On my first trunk mounted battery project I switched the negative. Not a race car and seemed the easiest. On my new project (also not a race car) I plan to switch the positive because I want to use the switch as a theft deterrent on occasion but keep juice flowing to an alarm (and maybe the radio to save presets). The switch will be for the big wire but I'll keep the alarm and/or radio hot all the time with a fused, non-switched wire.