During The War…G 10

Pretty hard not to get this one while doing everything else, it was the first achievement I got (during my first race). When an opponent is shot/hit/knocked off their scooter, you need to run over them while they're on the ground before they respawn on their scooter. This will probably happen right near the start of a race with everyone bunched up. If for some reason you don't get it naturally, you can go into a split screen/free roam game with a second controller and do it there.