Australian Competition and Consumer Commission (ACCC) data showed money lost to scams in the first quarter of 2021 was more than the total losses reported to Scamwatch in all of 2019.
ACCC warned scammers had begun impersonating defence personnel posting fake online listings to sell in-demand cars at below market value to lure potential buyers.
RACQ spokesperson Clare Hunter said often fraudsters would use sneaky sales tactics to increase the urgency of a deal.
"It's very worrying that in 97 percent of reported car sale scams this year, the seller claimed to be in the military and in a rush to sell their vehicle before being deployed," Ms Hunter said.
"Usually in these cases, the scammer says they’re in a remote area where an inspection is difficult, they ask for a money transfer before the car is be transported to the buyer and the car is often very cheap.
"The various forms of online marketplaces, like Facebook Marketplace, Gumtree, Car Sales and Ebay, have made it possible to buy a car from anywhere in Australia but it’s also made it easier for scammers to con victims."
Ms Hunter reminded buyers if it sounded too good to be true, it probably was.
"Unfortunately while used car sales have boomed, so too have vehicle scams, so we're urging people to be vigilant," she said.
"A price advertised well below the regular retail cost of the vehicle and sellers who ask for payment via third party websites should be warning signs for buyers.
"Make sure you never buy without seeing the car so you know it actually exists and be suspicious if the seller asks you to pay a deposit before you're able to inspect the vehicle.
"It's also always worth doing a Personal Property Security Register check on a second hand vehicle to ensure it doesn't have any money owing on it and it isn't listed as stolen or having been written off.
"If you think you may have been scammed, contact your bank as soon as possible, inform the website on which you were scammed, and report it to Scamwatch."