James and Ed, in the tree....
r33gts25 - if you are looking at doing timed sprints, you'll need to join a club that do them.
Southern Sporting Car Club do about 8 per year at EC, OP, OP south and Wakie. Run in conjunction with the WRX, HSV and Alfa clubs. Other clubs like Nissan Sporting Car club, Thornligh Car Club etc all them as well. Best to join one of them.
To get some practice, as Roy said go to many of the L2S days - OP hold the most and Wakie have all the "open days"
Theres a few of us in SAU NSW that do quite alot of the open / practice days. Feel free to drop into the NSW section
Cheers,
Chris