Saad Khan, 38, of Marsfield, appeared in Central Local Court via videolink from Silverwater jail on Thursday charged with detaining a person with intent to obtain advantage and two counts of aggravated sexual assault over the incident, which is alleged to have begun in Potts Point on December 8 last year.

The court heard at the time of the alleged offence, Khan was on bail for supplying and possessing prohibited drugs, particularly methylamphetamine, also known as ice.

Khan's lawyer Mark Dennis said his client is an Australian citizen who has lived in Australia since he was a baby. His family offered $20,000 surety and Khan offered to stay away from the Kings Cross area.

However, Magistrate Les Mabbutt said Khan has an extensive criminal history with numerous convictions for violence and if he is convicted of the aggravated sexual assault he will serve a lengthy jail sentence.

Last week, Burwood Local Court heard the alleged victim told police she and a friend, who had earlier visited the Wayside Chapel, agreed to "go for a drive" with Khan, getting in his silver Honda Accord in Darlinghurst Road about 11pm.

When the teen's friend got out of the car to buy a can of Coke from a 7/11 convenience store in William Street, Khan took off with the 15-year-old girl trapped in the back seat, court documents allege.

As he drove in the direction of Sydney Olympic Park, Khan allegedly asked the teen repeatedly if she wanted to "hook up" or "have sex".

She pleaded: "I'm not going to do that with you. Stop being a creep and take me back to 7/11."

Police allege Mr Khan grew increasingly angry at her rejection before pulling his car off to the side of the road lined with bushes.

"You make me feel like a piece of shit and you make me feel like a scumbag," he allegedly said.

He then allegedly forced the teenager to perform oral sex.

The Marsfield man is then accused of telling her to "lay down", pushing her chest until she was on the car's floor.

He then ripped off her skirt and underpants before forcing her to have sexual intercourse, the girl told police.

After the alleged assault, he agreed to take the 15-year-old back to the 7/11.

"Thank you, that's all I wanted," he allegedly said on the drive back to Sydney's CBD.

Mr Khan drove back to the Potts Point area where he was pulled over by Kings Cross police for driving an unregistered car.

He was allowed to drive off but the teen was taken back to the police station for an unrelated matter.

Police said the 15-year-old began to cry at the station and told them she had been sexually assaulted.

The teenager returned to her home on the state's central coast where she was interviewed by detectives on December 10.

Officers arrested Khan at Ryde police station on January 14 and charged him with detaining a person with intent to obtain advantage and two counts of aggravated sexual assault.

On Thursday, Mr Dennis told Central Local Court in relation to the drug supply charges, Khan admitted to having ice in his possession but claimed the other plastic bags seized by police contained "rock salt". The court heard he sells the drug to prostitutes in exchange for cash and sexual favours.

Mr Mabbutt said the sexual assault allegations will ultimately be decided by a jury based on the credibility of Khan and the complainant.

Khan was remanded in custody to reappear in March.