My neighbor at work just had his new 04 turboed this summer. Done by Dennis (themotorhead), they are good friends. Anyways, Dennis has HMF build a special can so you still have a right side can just like a 4-2-1 system. There still is one pipe at the fairing, but the other comes back just like a real exhaust. So for the most part, without looking close you'd never know the turbo was there. As far as sound, it's loader than the stock pipes, but quieter than my Micron race. To be honest, I can't even hear his bike when we are riding side by side over my bike, but he can hear mine. It's actually a sweet set-up (kinda a sleeper). Mostly custom by Dennis.......Mitsubishi turbo, carillo rods, custom inter-cooler.............about $9500.00 out the door on the friendship finance scale, have no idea what it would of cost the average joe. Anyways, about 350 rwhp with room for more if they decide to up the boost, can't remember what that is right now.