part the reason (i presume, cos i'm no mech engineer) for the Intermediate Driveshaft(s) is because the diff is not positioned smack-bang exactly equidistant between the L and R wheels. it is offset to the left. if you simply had a long R-side driveshaft and short L-side driveshaft connecting directly between the diff and wheels, you'd have all sorts of torque-steer/other havoc. so, the L and R drivershafts need to be equal length. which means there is the Intermediate Driveshaft connecting these to the diff.