The precise circumstances of the accident remain unclear, but the Finn's Polo was driving on a public road which looped back to the start of the test stage close to Leon.
There was a collision between the Polo and a family in another car.
The family members were attended to by the Volkswagen Motorsport doctor and were transported to hospital, where the father was diagnosed with mild concussion. The mother suffered a broken nose, while a child in the car at the same time was uninjured.
The team's test continued later the same day.
A spokesman from Volkswagen said: "The main thing is that nobody was seriously hurt in the accident."