A police spokeswoman said they were called to the incident south of Charleston on the West Coast at 12.55pm today.
The car had left State Highway 6 and gone about 10 metres down a bank.
A Westport News journalist at the scene said the rental car had been travelling north towards Westport when it went over a tight hairpin bend.
It plunged over the cliff and came to rest in bush after what firefighters described as a "frightening fall".
The three people stayed in the precariously perched car while they waited for rescuers to abseil down and rescue them.
Miraculously, none were injured in the crash. They were taken to Westport where they would be interviewed by police.
The car was retrieved by a tow truck but the road was still blocked on one lane this afternoon.
