The truck sound comes from large displacement and low revs.
http://www.v6mr2.com/V6t.wmv you can hear under heavy load and low revs it ideed sounds like a truck or muscle car. Once the revs pick up the engine sounds awsome. Its ALL ABOUT THE REVS!
BTW: max revs at any given point in that video were not above 5600ish immagine the sound at 7500 or 8000! I think the truck sound at idle is unavoidable with out a restrictive exhaust. It is, after all a V6.