On July 27, 1993, at approximately 1120 central daylight time, a Piper PA-28-161, N3079M sustained substantial damage during a collision with a vehicle while taxing at Houston Gulf Airport, Houston, Texas. The private pilot was not injured. One passenger in a moving motor vehicle sustained serious injuries and a second passenger received minor injuries. Visual meteorological conditions prevailed throughout the area for the planned local personal flight. During interviews, conducted by the Federal Aviation Administration inspectors with the pilot and local authorities, the following information was revealed. The passenger vehicle inadvertently entered the taxi area and proceeded at approximately 40 miles per hour toward the moving airplane. Impact occurred with the left wing of the airplane and the windshield of the vehicle. The wing and the main gear came to rest approximately 30 feet from the main wreckage. The Pilot/Operator Report revealed the following information. The private pilot was rated in gliders and endorsed for solo flight in the airplane. During the taxi, the pilot observed a car being driven down the taxiway. The driver subsequently turned the car around and was driving toward the airplane. The pilot taxied the airplane to the right side of the taxiway; however, the car impacted the left wing which separated from the airframe. The airplane slid to a stop on the taxiway. An enclosed witness statement indicated the passenger of the car and the driver were looking for a road and somehow ended up on the taxiway.