Corrected entry: Professor Fate's auto, when it raises itself off the running gear, has no means of propulsion. The drivetrain is not connected to the drive axles by either a driveline or chain.
Corrected entry: Note the scene were Professor Fate and Max are attempting a speed record with the rocket powered rail car. It appears the ignition of the rockets was much more violent than expected, as the crowd jumps in panic when the rockets fire, and retreat in disarray. This is so instantaneous that it does not look planned. Even the stunt doubles in the car cringe in their seats as the car takes off.