As long as the center of gravity does not get beyond the point of support, the vehicle will not fall over (assuming slow enough speeds). So it seems a buggy with the COG below the hub height (like a hammock hung between the two axles) should be nearly un-rollable. Also, the top of the chassis would tilt into the slope rather than out on off camber sections. How tall would the tires need to be to make this possible with a good breakover angle, maybe 50", 55" or so? Mid engine design? Rockwell axles for the huge tires?