Well in that case you could try a drive line disconnect. Anyone that attentive would probably realize that no one was home. I think a kill switch is your best bet though.
Are you getting out much? I would love to have a visitor up in GV and maybe go for a little drive. Perhaps you could show me an electrical thing or two and I'll buy ya dinner over at the Lakeside.
Sadly I haven't been to Green Valley in some time. I'll have to see if my friend will be up there anytime soon. I'd love to get back there before summer. Looks like they will have snow there today! I'll let you know!
I'll start planning a good hidden switch idea for you too! I'll PM when I work it out.