Oh, i've changed the box to a Lockable File Folder box (dimensions of 22"x16"x14") and have added "normal" motorcycle directionals, brake light, rear light, etc.
I've taken the box apart to add a 12" subwoofer and external 12v "power ports" like they have in cars.
I'm also added one of those inverters, that changes 12v into 110v 200w.
(I'm running all of my 12v accessories off a 12v SLA that's 105AH.)
Accessories = Lights, Directionals, Front Speakers, Front Power Port, Front Cigarette Lighter, FM/AM Radio, Satellite Radio, Two Amps, 12" Sub, Rear Power Port, Rear 110v Converter, etc, etc)
The rear box weighs about 35 lbs so I've added structural supports to the rear rack, which is attached to the rear frame as well as to my bicycle seat.