The BD9 now has a new C-clip type rear driveshaft axle, which is lightweight and contributes to a reduction in drivetrain weight and, consequently, rotational and unsprung masses. The part, which is primarily a Pro item since it is made of aircraft-grade aluminum and has a tough hard-coated surface but is not as sturdy as the steel counterpart and might break in serious accidents, is constructed from aircraft-grade aluminum.