Yeah thats why I have not done that. Its not really defeating thieves - if they want my car they can have it, insurance gives me a new one with all new accessories - haha!.... I work as an expat engineer and my car gets parked for 2 months at a time and to be honest I am tired of having to disconnect and reconnect battery terminals every time. I have now wired 2 isolator switches up front under the hood (1 for main and 1 for secondary). So the process now is open hood, isolate batteries, close hood, get in through the back door and lock 2 fronts, lock opposite rear, get out and hold the handle to lock the rear door... This still leave the trunk door unlocked but with the spare wheel carrier i park up against the wall and therefore a person cannot get in.
Was hoping that if i could just isolate with the car locked it would make my parking up process easier.