Every year thousands of Australians post second-hand cars for sale and for the most part it's a smooth ride.

But for Travis Barnard, doing just that left him more than $4,000 out of pocket.

He had offers on his 2007 Holden Captiva when he saw a Facebook plea from a young woman needing a car to get to work.

Travis felt very sorry for her and when she joked about wishing for an afterpay service, he stepped up.

The payment arrangement was an agreement for her to pay something every fortnight.

Over Facebook messenger, they agreed that would be $200, then Travis drove all the way to Busselton to drop it off.

Camera Icon Travis Barnard says the person who bought his car via an afterpay agreement has stopped pushing through the fortnightly repayments. Credit: Today Tonight

After that, silence.

“(I) didn't really hear from her, it was a huge struggle (before I) finally got $150 off her,” Travis said.

All up, she paid just $300 of the $4500 price.

She claimed in a message to Travis she hit a kangaroo and had halted payments.

Camera Icon The woman who agreed to pay for this car has paid just $300 of the $4500 price. Credit: Today Tonight

She told Travis her mechanic told her the car wasn't working because it hadn't been serviced properly - not because she'd hit a kangaroo.

He disagrees.

Either way, Facebook messages show she'd agreed to buy the car as is.

Generally there's no warranty for online sales on sites like Gumtree or Facebook marketplace.

Consumer Protection Commissioner David Hillyard said that “in 99.9 per cent” of circumstances, what you buy at the time is what you get and “you don't have a right of return”.

Camera Icon Buying and selling scams are on the rise. Credit: Today Tonight

It means clearly, the buyer is in the wrong. But not criminally.

“The police stated it was a civil matter (and) they couldn't do anything about it,” Travis said.

Buying and selling scams are on the rise.

Today Tonight can exclusively reveal 279 people reported buying and selling scams to Consumer Protection in 2018 - a 71 per cent increase on 2017.

They lost a whopping $1.7m, 81 per cent higher than 2017.

Consumer Protection recommends: when selling online, get the money, then give the goods.

“You wouldn't expect to provide people with unlimited credit, you wouldn't give up security and the vehicle by providing it to them straight away,” Mr Hillyard said.

“You’d expect to get payment for the vehicle first.”