On February 1, 2003, at 1110 mountain standard time, a Beech S-35, N6106V, collided with a car crossing the runway at Desert Gardens Airstrip, Quartzsite, Arizona. The pilot/owner was operating the airplane under the provisions of 14 CFR Part 91. The private pilot and one passenger were not injured; the airplane sustained substantial damage. The personal flight departed Palomar Airport, Carlsbad, California, about 1000 Pacific standard time. Visual meteorological conditions prevailed during the flight and no flight plan had been filed. The pilot stated that he flew from Montgomery Field, San Diego, California, to Carlsbad, and then filed IFR to Blythe, California. He arrived at Blythe, canceled his IFR flight plan, and continued on to Desert Gardens Airstrip (a dirt strip). A road crosses the runway, and a car pulled out to cross the runway. The pilot touched down and saw the car. He tried to go around, but the left main gear hit the car and sheared off. The airplane skidded down the runway and veered off to the left, which resulted in substantial damage to the wing and fuselage. In a telephone conversation with the National Transportation Safety Board investigator, the airstrip owner stated that the airstrip was marked with "stop" and "landing area" signs; however, the car did not stop before crossing the airstrip. As the car crossed the airstrip, it stopped. The owner further reported that the road crossing the airstrip was closed as a result of the accident.