It happened in front of a home on Graham Avenue, the victims told police.
The victims lost their cash and cell phones to the robbers, who were armed with a pistol, police said.
Police say the victims gave officers the phone number used to contact the seller of the vehicle they expected to buy. It was traced to the home of a woman in the city.
The victims had come to Arkansas from Stillwell, Oklahoma to pay for and pickup a 1998 Mercedes.
UPDATE: Friday, 10:30pm
An Oklahoma couple is speaking out about being robbed in Arkansas Wednesday.
Amondo Martinez says he and his wife were looking to buy a bigger car and saw what they thought was a great deal on Craigslist in Arkansas. When they showed up with their money ready to drive their new car home, they got much more than they bargained for.
After texting and talking to the seller they agreed to meet him at a home on Graham street on Wednesday. Martinez says two men approached the car with guns.
"They went through our stuff, reached in grabbed our cell phones and they saw the envelope they must've known had cash in it," Martinez said over the phone from Oklahoma.
The robbers stole $3,400 and two cell phones from the couple.
Police say another couple came to the same home two weeks ago and they too were robbed.
"Carrying around $3,500 and taking it to a complete stranger in a neighborhood area is not a good idea," says Sgt. Brian Dedrick.
Police say the ads were pulled off-line right after the robberies. The phone numbers used were untraceable because they from prepaid phones.
And the home is empty. KARK found this for rent sign in the grass and called the homeowner who says he hadn't been notified of the crimes.
After 8pm Friday, the victim notified KARK the same post that enticed him reappeared. KARK called the number on the post and no one answered.
The victim in this case said, he never got a name from the suspect or details like a VIN number.
Police are urging potential buyers to only meet sellers in public places.