A kinetic energy recovery and electric drive system for automotive vehicles comprises an electric pancake motor-generator (11, 211) having its stator housing (14, 214) coupled, combined or integrated with the gearbox housing (18, 218) of a gearbox (216) or final drive mechanism (16) and its rotor shaft (12, 212) oriented vertically and perpendicular to the drive-shaft (21, 234) or drive axle (20) of the vehicle. In certain embodiments the pancake motor rotor (10, 110, 210) may be fitted or integral with a perpendicular peripheral stiffening flange (113A, 113B, 213) in which is located a plurality of equally spaced permanent magnets (32, 132) of alternating polarity that electromagnetically engage with electromagnets (128A, 128B) of the pancake motor-generator stator. To facilitate retrofitting to existing vehicles the system may include an autonomous hybrid controller (316) that includes at least one sensor (322) to detect motion of the vehicle and/or motor without requiring any interface or integration with the vehicle's subsystems.