I also bought the tuner to tune the car, tried out 87 W/cai TBS and it is amazing sounds and feels much better and faster! The front strut bar is also VERY worth the money it improves handling immensely especially on making tight turns.
This is the insert (sleeve) that you remove IF you have a tune! if you don't have a tune you keep it in! its real easy to take it out, just unscrew and it slides out!