The tow plane collided with a van on the runway during takeoff. The van had been parked there on purpose by the airport owner to close the runway. He stated that he had notified the FAA of the closing but no NOTAM had been issued on 7/7/83. A NOTAM was issued for 7/6/83. The airport owner reportedly drove the van down the runway with the lights on and stopped about 1000 feet from the threshold with the intention of preventing the takeoff. The van was empty of occupants when the collision occurred. The tow plane pilot and his companions saw the van lights, but believed the vehicle would clear the runway. The tow plane vision was reduced by a camera and passenger (photographer) in front of him. During takeoff, the glider pilot saw the van would not be cleared and released his tow and landed on a taxiway. The tow plane did not clear the van and collision occurred in the middle of the runway.