Car Stolen During Test Drive With Seller's Young Son Inside

South Australia Police are on the hunt for a man and woman who stole a car during a test drive with the owner's five-year-old son still in the back seat.

The duo arrived at a Hope Valley home to test-drive a blue 1998 Subaru WRX at about 7.30 pm on Monday evening after seeing an advertisement for the vehicle online.

After speaking with the owner of the car the couple took the Suburu for a test drive, accompanied by the owner and his young son.

After a short ride, the car was returned to the property and the potential buyers asked to swap drivers.

That's when things got "bizarre", according to police.

The car had been advertised on Gumtree. Image: Google Maps.

The male suspect hopped in the driver's seat while the female moved to the back alongside the boy.

Before the owner had a chance to climb into the passenger seat, the driver quickly sped off -- with the man's son still strapped in.

The owner immediately phoned SA Police as he got into another car to give chase.

Thankfully, he spotted his young boy standing on the pavement, unharmed, about 200-300 metres down the road.

There has been no sign of the suspects or the car since.

Photo: SA Police

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On Tuesday morning, police confirmed they were still searching for the blue WRX with registration number S559APO.

"The male [is] described as Caucasian with a medium build, bald with numerous tattoos on both arms and legs, wearing black shorts and a white t-shirt," police said in a statement.

"The woman is only described as having blonde hair and wearing a white jumper".

Anyone with information on the incident or possible sightings of the vehicle are asked to contact the police assistance line on 131 444.

Gumtree has since released a statement confirming that "the safety and security of the community is our main priority".

"When selling a car, we recommend following these steps: We are a community site, so we always encourage members to buy and sell locally. For personal ease and safety, arrange to meet in a busy public place and take a friend or family member with you.

"For added peace of mind, it can be beneficial to ask a buyer to show their personal identification before you hand over any goods for inspection.

"We encourage our community to report any concerning or suspicious ads. We also encourage people to report any suspected unlawful activity to the police,” the website said.