Anytime you add an electrical accessory you probably give some thought to how it (or whatever it is connected to) can be removed from the bike without having to cut wiring or dive in under the seat or fuse panel again. This may be your solution.
It's a simple Coaxial DC power plug (RadioShack in this case but available from any electronics outlet). As shown above the male plug (right) can be mounted to a fairing, side cover, trunk or any panel on your bike. The female (left) plugs attach to the accessory. The coax connectors pull apart easily when you want them to but won't vibrate loose.
I have used one on my fairing (lots of electrical inside for radio, accessory outlet, antenna etc) and for my trunk (which has lighting mounted to the bracket. If there is a need to remove either part my electrical disconnect is taken care of with a single plug.
Coax is also a great way to connect yourself to the bike with electrical clothing.