Another option is to get a small flexible plastic sheet (some type of ABS resin, trill the holes in it so it matches up with the chassis screws and then mount a foam bumper on it like the on-roads have. That should absorb any impacts

I'm not quite sure off the top of my head how the bumper mounts on the 'pede.

BTW, this is what i was talking about when I said you can go all out on the Stampedes and build a monster of a car.
http://www.rc-monster.com/proddetail...PEDEKIT&cat=31