Rear Diff Subframe Solid Inserts are designed to offer improved support and reduce movement of the rear diff under harsh driving conditions, which helps reduce power loss through drivetrain movement and give a more solid positive suspension feel.
The OE bushes are very soft on the rear of the Impreza 07-14 models, although it helps reduce cabin noise and reduces the harshness of the suspension it does alter the handling quite a bit. These inserts simply press into the original subframe, the original bushes do not need to be removed when fitting these.
NVH (Noise Vibration harshness) will be increased using this product. Transmission noise from the rear diff on deceleration is increased with these inserts