Under covers for vehicle body

Under covers for a vehicle body, attached to the lower surface of the vehicle body in such a manner that, in the direction of travel of the vehicle, the under covers are located at positions in front of the rear wheels and in at least the rear half of the lower surface of the vehicle body. Grooves are formed in the surfaces of the under cover bodies which face the road surface. The grooves are arranged in pairs which face each other across the center of the vehicle in the width direction thereof and gradually approach closer to each other as the grooves extend rearward in the direction of travel of the vehicle. The rear ends of the grooves are located between the left and right rear wheels and are directed to the center of the vehicle in the width direction thereof.