I would like to point out (from a "scientific" standpoint) that adding lasers on it's back would be very difficult... for two main reasons, one being that you would have to try and find a way to make it all fit together so that it can roll up into a ball and still move around fine, and two, power draw... The power core of the droid may or may not be able to support more firepower, and the shields, while maintaining its operating system, and various sensors. I'm not the one who has a say on whether or not you can do it... just pointing out difficulties.