Caution tape could be seen wrapped around the six-seater vehicle, which was in the car park of the Waimatuku Hall in Thornbury.
Melted rubber lined the gravel surrounding the car, the interior of which was torched, with just the shell remaining.
The vehicle was close to a farm fence but the fire did not appear to have caused any damage or spread to other structures.
A police spokeswoman confirmed officers were alerted to the fire about 12.15am on the Wallacetown-Riverton stretch on State Highway 99.
There were no people in or around the vehicle when emergency services arrived.
The fire had been noted as a potential arson and police would be investigating.
A Fire and Emergency New Zealand spokesman said crews were sent from Thornbury and Wallacetown and arrived to find the vehicle well-involved in flames.
It took them about an hour to put out the blaze.
