Pete,
We have run the Postie Bike Challenge for 10 years now (40-60 riders on Honda 110cc stepthroughs) 3,000km through the outback. They travel at 70kph and we have never had a bike run down. A CMP is a heck of a lot bigger target so you will have no problem. You must spend $150 and get a UHF radio so you can talk to the road trains and other trucks. You will find they are some of your best salesmen and will spread the word.
We had great support from them on our prostate cancer trip in the 1915 Willys Overland
www.willys.com.au Feel free to use any ideas from our trip to plan yours.
Lang