[elhigh]

The demo has merit, and it just echoes what lots of people have been saying here for a long time: wheels are draggy. Smooth out as much of the airflow over them as possible.

I can't remember who said it or in which thread, but I liked one answer to the wheel drag question: skirt the wheel well, and add smoothie discs to the wheels too. One reduces the air resistance experienced by the wheel itself, and the other reduces the skin drag of the entire body. Win-win.

With your offroader, you'll have to get a little creative. Your tires may project beyond the body line, so skirting the wheel wells may not be a viable option, or it has to be a modest one. If everything is done with a stock look so the tire shoulders don't project, then skirts are an option but you'd still want to be able to remove them easily when you get to the mudholes. Probably the same goes for any wheel discs you add, since if you leave them on then the wheel will just pack up with mud behind the disc.

Air dams might be helpful, and some belly pans. If you're into hard rock trails then belly pans shouldn't be a problem, but if you're a mudder then again I would strongly recommend designing something that is easily removed before hitting the holes.