Tony at Loveday (where the Riverland Challenge was held) is holding a Mud Drags Event on Feb 3 2007 At his property it will be a fantastic event consisting of vehicles from standard to competition.
Entry is $10 per vehicle and $10 per person. I will only be there for the day so I am not sure of the cost for multiple days.
Check out their web for more info.
www.loveday4x4adventures.com