She scratched the attacker's eyes, causing him to scream and retreat to his car, driving off along SH1 towards Cambridge.
Police spokesman Andrew McAlley described the attempted abduction as cowardly and praised the young woman for doing "all the right things".
He would not say if police thought the attack was random or if they held concerns for other women in the area.
"It's the only incident of that nature we know of and we're appealing for information so we can make a considered opinion. We always urge people to use common sense."
Mr McAlley also criticised the two men in the back seat for not intervening.
The bar manager, who did not want to be named, described the young woman as polite and hard-working.
"She's lovely, and shy. We've never had anything like this happen before."
The attacker was described as a dark-skinned man aged in his mid-to-late 20s with an Indian accent. He was wearing a blue short-sleeved shirt, shorts, sunglasses and his hair - black with blond tips - was tied up.
His car was described as a late model dark or black sedan with tinted rear windows.
Anyone with any information on the incident or who may be able to identify the attacker is asked to contact Detective Sergeant Nick O'Brien on 07-858-6200 or Crimestoppers, anonymously, on 0800-555-111.