Out of all the popular cities in Australia, Adelaide is the cheapest city to rent a car in at just ฿598/day. Renting a car in Adelaide is 67% cheaper than renting one in Perth where the per day rate is around ฿1,790. Other fairly inexpensive cities in Australia to get a rental car in are: Brisbane (฿623/day), Melbourne (฿659/day), and Sydney (฿1,002/day). While these cities typically have cheaper prices than the rest of the country, travellers looking to rent a car in Sydney should expect to spend around ฿1,002/day on their transportation. The most popular city to rent a car in Australia is Sydney.