It seems logical to me that Tesla will want to come out with a four motor car at some point. It seems like this would give you truly the ultimate AWD possible. You'd have instant control of the traction on each corner of the vehicle and none of the inefficiency of differential gears so it should get more range too. You don't want the motor mounted in the wheel because of the unsprung weight so they would likely be mounted inboard near the suspension linkages and connected to the wheels with short half shafts. This also opens up a whole lot more possible space in the vehicle. Maybe you could even have a tunnel to the frunk for very long objects like 2x4 planks that could pass from frunk to trunk.