Go with at least two cars.
"I'm going to do something now they used to do in Vietnam. It's called making a head on a stick." Mick Taylor, Wolf Creek
In 1975 I saw an unforgettable Australian "disappearance" film, Picnic at Hanging Rock.In 2005, I have recently seen another Australian disappearance film, Wolf Creek. Both are set in popular South Australian hiking spots, but there the similarity ends because Peter Weir's Hanging Rock cradles ambiguity to the extent you never know what happens to the women who disappear. Greg McLean's Wolf Creek unambiguously parades violence to a level that shows in the goriest possible detail what happens to each principal.
The three young people who set out on a long journey in the outback meet various fates at the hands of Mick Taylor, played by John Jarratt, who also appears as benign but worldly working class boy Albert in Hanging Rock. As friendly as he is to the girls in that film, he is equally as brutal to them in Wolf Creek.
The requisite horror film set up is masterfully done: Little clues about the impending doom are peppered throughout but only lightly because the dominant theme in the first third is how innocently happy this trio is, whether it's cavorting at the beach or balancing the emerging love between the only male and one of the females against the good of the group. Easy stuff considering the hell to come.
Why should we even brook another film in this slasher/horror genre? It's hard to figure except that the young people, and even Mick himself, are smart and engaging, quite a bit different from the usual dimwits who set themselves up for disaster from the first frame of the usual horror flick. These young adults are good people, and for a while match wits with an Aussie Hannibal Lecter to their credit. As in the case of Silence of the Lambs, don't expect good to conquer evil or the slasher to be vulnerable. The modern world has too many perverts waiting to trample the cadavers of idealistic undergrads. Let Wolf Creek serve as a cautionary tale for women who jog alone at night or young men who aimlessly wander.
Gus Van Sandt's journey film Gerry is a quiet preparation for the otherworldly tourist site/meteor crater in Australia known as Wolf Creek. Go with at least two cars if you must.