Have a small amount of car driving talent and either several million dollars to effectively bankroll your own team. You could have personal sponsors worth a few million if you don't have the cash.
Start as a 7-9 year old in go-karts, then formula Ford, maybe formula 3000, maybe some sport sedans, then do a few years in Europe getting a name for yourself in some enduros like 24 hour races, then get a gig in the Australian GT cup, maybe an enduro drive or two as a guest. Maybe then get a drive in the Fujitsu series and win that series, then if you are lucky a drive for a backhalf team of the main game, then a better drive and better drive, then you are a V8 Supercar star ! PS: Take about 14 years.