I was watching a a "Mythbusters" rerun where they were experimenting with bus rollovers a la "Speed", and it got me thinking about the physics of vehicle rollovers. Applying my basic physics knowledge my intuitive understanding of the process is that it occurs because the reactive centrifugal force on a vehicle having a high center of gravity causes a net torque on the vehicle that wants to push it over. Is it true that if it were possible to perfectly balance the mass of a vehicle, that it would not roll as the torques would always be perfectly balanced? Does the center of gravity define the axis of the rotation of the vehicle when it does begin to roll? The countermeasure in the film and in the TV experiment replicating the film was to redistribute the mass to the side of the vehicle that was tipping upwards. This was described as redistributing the center of gravity, but it seems to make more sense in my mind that they were using the mass and gravity to provide a torque counteracting the torque that was causing the roll. Are these two views equivalent, or is my understanding incorrect? Thanks for any insight.