The man and woman, believed to be in their 50s, sustained only minor scratches in the crash, which resulted in emergency services from Queenstown and Glenorchy- including a helicopter - rushing to the scene.
However, the couple managed to extricate themselves from the vehicle and walk up to the road, where they were assessed by St John staff and interviewed by Queenstown police.
Sergeant Steve Watt, of Queenstown, said the couple were ''fit and well'' following the crash, which happened opposite Pig Island, about 4.15pm.
Sgt Watt said preliminary investigations indicated the couple had been travelling from Glenorchy towards Queenstown when, according to witnesses travelling behind, their rental car began to drift to the right-hand side of the road.
''It has proceeded to veer over to the right and completely over the bank, where it's gone down approximately 50m and come to rest.''
Tyre marks were visible for several metres leading to the point the car went over the bank.
The rental vehicle remained at the crash site last night.
Sgt Watt said the driver of the vehicle had been charged with careless driving and would appear before a justice of the peace in the Queenstown District Court.
It is the most recent in a spate of incidents involving overseas drivers on South Island roads.
In November, three Hong Kong tourists were killed and another seriously injured after the rental van in which they were travelling collided with a truck and trailer unit on State Highway 6, near Luggate.
That same month, a 27-year-old Shanghai man, whose rental car collided with another vehicle near Queenstown was convicted in what a judge said was a ''classic case'' of why tourists should sit a driving test.
The driver admitted a charge of dangerous driving relating to two incidents near Queenstown.
In one, he crossed the centre line by about 2m and collided with an oncoming car.
The driver was convicted and fined $600, court costs of $130 and disqualified from driving for eight months.
In September a 66-year-old Hong Kong woman was killed when the car in which she was a back-seat passenger collided with an oncoming vehicle on State Highway 79, between Geraldine and Fairlie. She was not wearing a seat belt and was thrown from the car on impact.
The driver, her 27-year-old son, of Melbourne, appeared in the Christchurch District Court last week of careless driving causing death and careless driving causing injury to his sister.
He was convicted and discharged on both countsFor careless driving causing injury to a 72-year-old man, he was convicted and ordered to pay $3500 in emotional reparation.
He was disqualified from driving for 12 months.
