The woman made a bid for freedom from the late model sedan's boot by jumping from it as it travelled along Huia Road in suburban Papatoetoe last night.
"We want to assure the public we are doing everything we can to locate the person or persons involved in this crime. However, we still need members of the public who saw anything they think may be relevant to contact us," Counties Manukau Crime Manager detective Inspector Dave Lynch said.
There were officers who were fluent in Thai and Chinese assigned to the case, he said.
Mr Lynch said police were still trying to identify the car which they believed to be a late model silver sedan.
He said a car following initially gave chase when the sedan sped off but lost track of it and did not get a clear look at its registration plate.
They appealed for anyone who saw a vehicle fitting the description in the surrounding area acting suspiciously to contact them.