Never let the exhaust openly vent *under* the truck. If you have to cut the down-turned rust-tip off, put on a similar chrome/stainless tip, or a straight tip. I have a slash-cut, stainless and welded tip offset slightly to the outside and just far enough under the bumper to prevent it from getting knocked off by a "bumper car" paralell parker. It takes one idiot in a small car to wreck your exhaust with a bump if it protrudes beyond the lower bumper. Don't let exhaust go *straight* back either. In the vacuum behind the truck, exhaust can build and sometimes be pushed in through the rear vents. (Think dusty roads and how your rear glass gets packed with dust after just half a mile) If you go with a straight pipe, make sure it is offset like mine to the side to catch the airstream that slips by the rear passenger-side tire and you'll be safe and look sharp.