I wonder has Tesla (or anyone else) considered a drive chain design with a motor for every wheel? On the face of it this would enable a much simplified mechanical design with consequent weight and space savings and increased range (less inertia and more space for batteries). There would be no need for trans-axels or differential gears as these functions could be incorporated in the drive control electronics. Both the drive and the regenerative breaking could be further optimised and features such as limited slip differential for off-road use could be implemented in software. I also wonder why designs do not rely on regenerative breaking always (perhaps with an emergency backup friction system which could be shared with parking break functionality). This could be accomplished by using a heater/radiator to dump electricity if the batteries are full or if generation exceeds the batteries capacity to absorb energy. Such a system should be more reliable, eliminate break wear and offer the possibility of more precise control.