This trophy can prove to be incredibly tedious. First of all, you will have to locate a vehicle. These tend to spawn at set locations throughout the map, so try to remember where they could potentially spawn. In regular play, 10 kills while in a vehicle would take quite a long time. However, killing downed enemies counts towards this trophy. Play either Duos or Squads, find a vehicle and then proceed to search for a lone enemy. You must be the person that has downed the enemy in order for it to count. If you finish off someone after your teammate has downed them, it will not count towards this trophy.