Perrin first released their brass shifter bushing to help reduce some of the play in the 2015 WRX's cable actuated shifter. However, that didn't help with the slop with the topside of the shifter mechanism. You can now add the Perrin Shifter Stop to the shifter mechanism to create a more confidence inspiring shifter gate. Due to the slop of the internals in the transmission, there is an unacceptable amount of horizontal slop within the 1st- and 2nd- gear shift gates. What should be little to no movement ends up being nearly 1.0 inch of play. This makes for an unnatural placement of shift gates and a lost feeling of which gear you are in. The Perrin Shifter Stop removes this play, reducing the horizontal movement to 0.12 inches. This makes for a solid connection between the driver and transmission.