Supersonic car on a highway?

[Artlav]

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?

 

[rcgldr]

Supersonic aircraft make low passes without any harmful effects on most objects. If it was extremely close and large enough, some damage could occur. Example of a fly by between two navy boats (2nd half of video), note that the sound of a shock wave is like a crack. The boom doesn't occur until there's enough distance between super sonic object and listener that the shock wave dissapates into a normal but loud sound wave.

http://jeffareid.net/real/f14flyby.wmv


Also during experiements, jet aircraft are flown into the shock waves produced by other aircraft, again without damage.