The Cobra Nationals is hosted by the NSW Cobra Car Club. It's held at Wakefield Park Raceway in Goulburn NSW on Friday 28th September thru to Sunday 30th September.
Events include timed sprints around the main circuit, a hill climb, 1/8th mile drags and a go to whoa. There's also usually a Show and Shine in downtown Goulburn Saturday morning prior to heading out to the track.
Check out the NSW Cobra Car Club web page for details and entry forms:
NSW Cobrea Car Club
Cheers
Edit: Beat me to it Craig