i'm gonna have my exhaust coming out the back, and the sides. i'll have a valve to cut the flow from either the back, or to the sides.
the back exhaust will be nice and quiet. so when someone roles up on me, they'll think i have nothing. then i'll close off the valves to the back, open the side, and the sound will be thunderous!! and i'll blow my exhaust right in the guy's window, and take off!!!