I've seen it both ways - left alone, and with an extension to exit out from under the vehicle under the bumper. Mine is out the side, with a cut into the plastic bumper cover, done before I bought the truck. Not how I would have done it, but I don't dislike it enough to spend the money to get a new bumper cover. I don't have a lift, but I can imagine with one, it would look better to have something exiting from the vehicle if the cut-off pipe can be seen.