Antchik said he earns about A$16,000 per year by leasing a ute and sedan. But it's not as lucrative as it looks. Once he has paid for registration, a monthly membership fee of A$60 on each vehicle and other costs, he is left with a total profit of about A$1000-A$2000 per year.
"It's really so I can have the cars and use them when I want but still make money when I don't need them," he said.
"They're positively geared assets."
Antchik said he paid about A$23,000 for his ute and has made about A$18,000 — before paying costs — renting it out for A$7 per hour or A$35 per day, over two years.
He also leases out his Ford Focus for a similar price.
"It's based in Pyrmont so we get lots of travelling people and students booking it out for the weekend ... we get about A$6000-A$9000 a year for that one," he said.
"The (car sharing company) takes care of all the marketing and organises secure drop-off and pick-up boxes for the keys.
"I just leave the car parked near my place and borrowers can find it (on the website) and return it there when done."
Antchik said some renters had caused "minor damage" to his cars but that comprehensive insurance was included as part of his membership with the car sharing business and had repaired them at no extra cost.
"I wouldn't say I make a lot of money by doing it," he said
"But I'm not really doing it for the money. I genuinely need the car and this is a way to have free use of it for the occasional usage pattern, and make a bit of money in process."
As many as 1.5 million Australians could be using car-sharing services within 10 years, according to Roy Morgan research that last year predicted big changes for the automotive industry.
Quickar spokesman Scott Browning, who helped analyse Roy Morgan's survey of 50,000 people, said the average Australian car sits idle for 23 hours a day. He said many people no longer see cars as a means of freedom because there are so many other transport options.
"It's become very attractive for millennials, particularly those who own one car, who are searching for a second car, or the first-time people buying a car who now think they don't need [to buy one]," he said.
There were 18.8 million registered motor vehicles in Australia as at January 31, 2017, according to the Bureau of Statistics. The ABS' latest statistics show the national vehicle fleet grew by 2.1 per cent between 2016 and 2017.
Davies described the increase as a "mind-blowing ... waste".
"Why would we want to keep building cars for this insanely wasteful system?" he said.
"We really need to be scaling car use back and making use of the resources we already have.
"The way people get around needs to move away from the old 'one person, one car' model. "With the shift to access over ownership, peer-to-peer sharing is going to be the fastest way to unlock the idle capacity of that massive fleet of existing cars we already have."