From the sounds of it, your crash bar gets hacked to a point where it wont do you much good. This is a very important part of your car. If you never have passengers in your car, then hey, go for it, but otherwise I'd thing twice.
There is a very cheap part that replaces the factory bumper bar:
http://www.enjukuracing.com/products...Scion-FRS.html
It's not going to crumple in the same way that the car is designed to, but
if this bar clears, and works with the Greddy kit, You should consider it. Could save a life.