[MrForbes]

This is our bumper mount system. The hex shaped standoffs are bolted to the chassis, and touch the bumper, but do not attach to it. The long coupling nuts in the corners are threaded onto the "fanged elevator bolts" that are mounted inside the bumpers. We used the long nuts to make it easier to handle the nuts without dropping them into mysterious crevices, and to have a lot more area to put the wrench on them.