A few more details:
I made a small bracket to help hold the rx in place. The rx is mounted with d-tape but since it was so close to the spur/driveshaft I didn't want to chance it coming loose and getting sucked into the gears, so I made a bracket that mounts to the steering servo mount and clamps down on the rx. I also made a bracket that helps support the motor wires (keep flexing to a minimum) and keeps them from getting tangled in the driveshaft. I also added velcro straps to the battery box. They are more secure and allow for taller batteries to fit.
All the electronics mounted low on the chassis.
I made a small bracket to help hold the rx down.
A wire support to keep the motor/esc wires out of the driveshaft.