A kinetic energy recovery and electric drive system for automotive vehicles comprises an electric pancake motor-generator having its stator housing coupled, combined or integrated with the gearbox housing of a gearbox or final drive mechanism and its rotor shaft oriented vertically and perpendicular to the drive-shaft or drive axle of the vehicle. In certain embodiments the pancake motor rotor may be fitted or integral with a perpendicular peripheral stiffening flange in which is located a plurality of equally spaced permanent magnets of alternating polarity that electromagnetically engage with electromagnets of the pancake motor-generator stator. To facilitate retrofitting to existing vehicles the system may include an autonomous hybrid controller that includes at least one sensor to detect motion of the vehicle and/or motor without requiring any interface or integration with the vehicle's subsystems.