James,
I appreciate I dont know your laws as far as modifications go but if you have the need to replace something you also have the opportunity to improve something. The standard SVX exhaust set up (apart from the exhaust manifold) is a dog. Get yourself down to a performance based exhaust specialist and look to minimise as much of the original crap as you can (still complying with your laws). Off the line speed suffers a little but acceleration over the power band and the note makes it worth while.