I have my own mod, for my rpm bumper, the middle two holes which the diff sits through i cut slits in so that i can just undo the two screws holding the front arm mount on and pull the bumper off, saving undoing the diff, this way if you break a front wishbone its really easy to change it fast. Also i just sand my hinge pins down a little bit until they are steel coloured and not black, allows the wishbones to drop freely.