The body of Olwyn Cowley, 21, from Brackenfell was found at Monwabisi Beach in Khayelitsha on Friday, reported the Weekend Argus.
Cowley’s girlfriend (who was not identified) said he was last heard of when leaving to meet the prospective buyer. The BMW was later found abandoned in Mitchells Plain.
Three men were arrested for murder, hijacking and kidnapping after they tried to sell the car.
A police spokesperson said Cowley had been shot in the head.
An aunt of Cowley’s said he had met one of the men he had wanted to sell his car to before but the man didn’t have the money.
He asked for time to come up with the money and then called when he supposedly had it.
“Olwyn had his name and ID number, but police records show it was a fake name, although the ID number was real,” said his aunt, Anita Hanekom.
Cowley had apparently advertised the car on online classified website Gumtree.
A woman was gang-raped and killed last year after answering an ad on Gumtree for a job in Observatory, Cape Town.