The Whiteline Flat Out Positive Shift Kit for the WRX and STI is an effective option to crisp up gear shifts. The Positive Shift kits include simple poly bushings that replace the soft OEM units, and the Motorsports version offers still a firmer bushing. This kit stiffens up the transmission mounting point that is underneath the transmission itself. The Whiteline Positive Shift Kit is great part to add to your WRX/STI at the same time you upgrade your transmission mount. The Whiteline Positive Shift kit installs easily with simple hand tools. All necessary hardware and instructions are included.