May not be the bush... I have replaced mine but its (CTR) still rattling at top speed. Suspecting may be the Euro R Shift Knob. Some say you need to put a screw at the base. Any Opinion.
i dont know what it's called but in J's Racing catalog ( in Chris's place) got this blue kaler thingy look like the silicon bush which is said can improve such problem with the shifter....i dont remember how much it costs also....