On August 26, 1995,at 2115 eastern daylight time a Piper PA-38- 112 was substantially damaged following a collision with an automobile during landing at Kissimmee Municipal Airport in Kissimmee, Florida. Neither the airline transport/instructor pilot nor his student were injured in the accident. The aircraft was being operated under the provision of CFR Part 91 by the instructor pilot. Visual meteorological conditions existed at the time, and no flight plan had been filed for the instructional flight. The flight departed Kissimmee, Florida at about 2100. According to the pilot, he was executing a simulated forced landing at the airport. They observed the automobile approaching the runway during the final approach. They thought the vehicle had stopped and continued the landing. After touchdown, they observed the vehicle crossing the runway in front of them, but could not avoid the vehicle. The driver of the automobile, who was employed at the airport, stated that he did not see the aircraft approaching the runway prior to his attempting to cross the runway. Investigation revealed that the anti-collision lights of the aircraft were not operating prior to the accident.