In Nanjing, China, during a Tesla Model S test drive (official or unofficial, we're not sure), the electric car collided violently with a Mazda 6.

Specific details are very sparse, but we do know that all of the occupants in the Model S are okay.  There's no word at this time on the status of those in the Mazda 6, but its damage looks much less severe.

Wrecked Mazda

Wrecked Mazda

Lastly, an image of the Model S shows the rear of the vehicle.  There's no license plate, which would seem to indicate it's either an unregistered car or perhaps a manufacturer's vehicles.

Source: Car News China