The Beatrush rear trunk bar for the Subaru WRX and STI features lightweight strong and rigid aluminum construction. It improves rear strut and chassis rigidity by forming a cage on the rear chassis of the vehicle, preventing chassis distortion due to heavy driving. This rear trunk cage must be used with the Beatrush Rear strut tower bar for installation. Will not work in wagons, only sedans.The Beatrush Rear Strut Tower Bar is a lightweight and rigid aluminum brace. It connects from each strut tower top hat to help link both sides of the chassis all together as one. This strut tower bar will fit sedans only, and will not fit in the wagon.