Looks what this guy is suggesting should be used on the mongol rally (second post, third car down)
http://www.mongolrally.com/modules....c&t=1293&sid=e7f95811412481a34f76d52adbe695a0
http://www.mongolrally.com/modules....c&t=1293&sid=e7f95811412481a34f76d52adbe695a0