The present invention includes a propshaft assembly that has a propshaft connected to a transmission and an axle and a center support that attaches the propshaft to a vehicle. In one aspect, leaning manager includes software that can be implemented on any type of computer device for tracking andor coordinating the buying and selling of available market quantities by multiple automated or semi-automated trading tools. In this way, the hinge will be completely invisible when the door is closed, and also inaccessible from the outside.