This is probably going to be a stupid question, but i am pretty stupid.. im not really after a performance gain by getting a new exhaust, just the sound. Would changing the back box get the desired effect im after or would i be looking at a full system. There is a video on youtube of a red agp with the g-tech exhaust pulling away and it sounds.. good to say the least! do you reckon that would be a whole new system? I would get the link but im on my phone..