A car-sized device is running along a light-traffic highway at slightly above the speed of sound. It is unmanned and equipped with powerful RCS and flaps to make the tight turns around other cars and road curves, thus following the road. The jet engine is tilted slightly upwards and points above the COG, thus preventing jet wash on the surrounding, pushing the device to the ground and countering any lift torque. The questions are: 1. What will be the destructive magnitude of this disaster to the cars on the road and surrounding scenery/countryside buildings? I suppose the shockwave should be the main problem, but have no idea how big it is. 2. And, is there any real or slightly handwaved way to counter the destructive effects to somewhat acceptable limits?