Try rear wheel steer with front wheel drive. It don't work at speed. All who have tried failed. The test vehicle had a few problems as well. Being the SST was a thrust driven vehicle the traction or lack of were out of the picture. It's two different worlds, Andy said never again.
You could Tell by his Breathing he was really having a heck of a time keeping it undercontrol
! He's either the Bravest or Craziest Driver/Pilot I Ever seen
? I don't think to many Driver's would have stayed in it during that after burner Yaw
!!! My Hat's off to Andy Green,and his crew.