I've been reading on another diesel forum, and it seems like some folks say a muffler on a turbo diesel isnt necessary? The sound clips sure were sweet. Also, I still want to route the exhuast to the outside of the frame rail, and then dump it down a-la lightning style right before the rear wheel. Not having a muffler would make this process easier. This is so I can fit another 35 gallon fuel tank inbetween the frame rails.