They deliver throwing projectiles to athletes. Designed by Toyota for competitions in throwing spears, nukes and disks, as well as rugby and other sports where something can fly far away. After throwing, the car is sent to the place of the fall, a person loads the projectile into it, and it drives it back. In general, such gadgets help in competitions for not the first year, and once upon a time radio-controlled models were used for this purpose in general