What would happen if a family car smashed into a wall at 120 mph??? Watch the video below – the fastest test that has been conducted so far. This crush test is from Fifth Gear. They used a Ford Focus, to find out how much of the car will be left without any serious damage, after the crash. At a speed of 120 mph, the Ford Focus went to 0 mph within just 60 milliseconds. The car hit into a concrete block with the mannequins subjected to forces of up to 400g.