The Whiteline rear subframe bushings (also known as the Positive Traction Kit) replace the stock soft rubber units with their signature stiffer polyurethane units. These harder bushings eliminate all the rear sub-frame movement during hard lateral loads, helping reduce snap oversteer while providing crisper feedback from the back end of the car. By reducing the shifting of the rear subframe, the back of the car will break loose much more predictably unlike the stock bushings that snap back when they are unloaded. Bottom line is your Subaru will be much more enjoyable and predictable to drive.