It seems logical that the four-wheeled Ferrari's FF and LUSSO have a major design flaw in the PTU concept. The motor is extra vulnerable to motor destruction when the PTU fails, unfortunately many PTUs are failing but luckily not always with engine destruction. The PTU is connected directly to the motor and if something goes wrong with the PTU, it is possible that damaged PTU parts will contaminate the motor. I know at least two cases where the motor was destroyed after PTU failure. My Lusso lost oil on the PTU as it disappeared without a trace and later on the engine was destroyed. I know several FF owners who had to exchange the PTU. Can Ferrari guaranty that a malfunctioning PTU is no danger to the motor, i guess not, the PTU concept no matter how genieuce, it is still in infancy. An other point that puzzles me is that the PTU (in yellow on the foto) is a small box compared with the rear gearbox which is about the size of a V12 motor clearly to adapt to big power changes and loads. It doesn't make sense to have a small gearbox that must be capable to cope with high power loads. Image you are driving manually 120km/h and and by accident you switch in second gear. Do you think this small gearbox is capable taking this load. one could say: This might be the reason that a lot of PTU are going bad after heavy use and some even destroy the motor. I think the Lusso is due to this design a very fragile car.