We have a similar event here in Texas. It's called the Big Bend Open Road Race
http://www.bborr.com/
Three of us from the Houston Cobra Club are signed up to run the week of April 21-24th.
If anyone knows of a helmet to helmet communication system for between driver and navigator I'm looking to purchase one. The open cockpit makes it impossible to communicate verbally and going 90- 124 mph hour I don't want to be looking for hand signals.