Do you autocross your Impreza? Adding a racing harness to your car will dramatically help you lower your times by keeping you planted to the seat. Your 3 point seat belt is great for the street and keeping you in place as designed in an accident. The factory belts and the entire car have been designed knowing the way your body will move in an accident. For autocrossing where you want to remain one with the seated so you can feather the clutch and heal-toe. The only way to accomplish that is with a 4 point harness.