The married couple — a German man and a Japanese woman who live in Japan — were driving on North Grampians Road at Wartook when the driver lost control about 4pm.

Police believe the slippery conditions and a lack of familiarity with the road may have caused the woman, 31, to lose control on a bend.

A police media spokesman said the car flipped end-to-end several times as it plummeted down the embankment.

The man, 34, managed to free himself from the car, but his wife became trapped behind the wheel.

The man was climbing up the embankment to call for help when emergency crews arrived.

State Emergency Service Mid-West Region duty officer Mark Cattell said a crew from Stawell was first on the scene, with a crew from Ararat called soon after due to concerns about the stability of the car.

"It probably took at least 45 minutes to get good stabilisation on the vehicle and then crews extricated the lady from the car," he said.

"They were initially going to winch her out with a helicopter but there were concerns that that could destabilise the vehicle, so they put her in a stretcher, set up a hauling system back up to the road

and manually hauled her up to the road where an ambulance was waiting."

An ambulance took the woman from the scene at 7pm.

Ambulance Victoria spokesman John Mullen said the woman, who was take to hospital in Horsham, was lucky to escape with only minor injuries.

Her husband was uninjured.

Mr Cattell said the corner where the accident happened was one of the only bends on North Grampians Road without barriers.

The vehicle will be recovered today.