I thought I heard or read a review on here of somebody who had the G-Tech on their AGP, and although liked the noise when marching on abit found it really drony on long motorway runs, which to be honest is a pit fall of most noisy exhausts.
Like mentioned any exhaust shop can change an exhaust unless there's gona need abit of fetling ie not for your model and needs adjusting which is where an custom exhaust shop comes into their own