The Rémi Gaillard Radar prank is an instant classic because it includes all the elements of a Rémi stunt: simplicity and the video ending with Rémi Gaillard being loaded into a cop car.
In this video, Rémi dresses up like a radar machine and stands by the side of the road. When cars go by, he flashes a light so the people in the cars think they have been caught speeding. He then proceeds to chase after them with only his legs sticking out of his metal body. But Rémi isn't only slowing down cars, he is also trying to flash his light at tractors and airplanes (they don't seem to notice him).
Finally to top it all off, Rémi flashes his light at a police car who immediately backs up to investigate. Rémi takes off running but is eventually tracked down by the policemen. The Rémi Gaillard Radar prank continues to add to Rémi's never-ending police record.