where did you get the overlays from and what percent is it? the exhaust looks sick you shud post some sound clips of it.
Lets keep the thread on topic please. And $454 is great for a HKS exhaust their product is fantastic. Remember guys this is a exhaust from a major company that gives you high quality service and product. And in reality it really isn't expensive especially considering it is a full cat-back setup. You could bolt this on in your drive way within an hour.
in the very first post i mentioned what it is... "The sound resonator is a small resonator chamber that is welded to the top of the muffler that allows your exhaust note to stay just under 95db and ends up giving you a nice solid deep tone without being overly loud or annoying"