I have a Response with an internal tailpipe. The older argo bodies have more room I think to route it. The avenger/frontier, with the lower areas beside the front seat, appear to prohibit my design, as you need a double wall construction with air flow, at least on mine.
You could run a pipe down the outside.. I did at first. I suggest a perforated heat shield, motorcycle style. It would take some work, to make it safe for the passenger. Probably a coated or wrapped pipe, also. Will take some effort to not have it stick out past the rubber skirt and get bumped. Otherwise if you had a windshield you could run it upward.
To Invent, you need a good imagination and a pile of junk. (Thomas Edison)