SLR Speed - BMW E46 Solid Subframe Bushings / MountsIn addition to giving more driver feedback and immediate response from the suspension and drivetrain, solid subframe bushings reinforce the rear body and frame of your car. This makes the subframe an integral structural member of the rear unibody instead of a rubber isolated floating member. This can help avoid the notorious E46 stress cracks in the body around the subframe mounts by eliminating the ability for the subframe to move and cause that flex