Jari-Matti Latvala's VW Polo R WRC collided with another car on a road section when the team was testing in Mexico.
Latvala, who recently left the Ford team, was testing the Polo R WRC alongside his new teammate Sebastien Ogier.
The Finn had the accident on an open road as he was reaching his test base.
The other car, which arrived from the other side of the road, hit the Polo R and rolled down. The Mexican family that was inside the car, a man, his wife and son, sufferd from light injuries. Latvala and codriver Mikka Antilla escaped unhurt from the accident.