This quest can be quite challenging because it requires another player to be inside a vehicle and that doesn't happen as often as we would like for this sake of getting this quest done.

Vehicles can be any type of vehicle so if you see a player inside a car, truck or boat start shooting.

I tend to find players in vehicles near roads in a car or rivers in a boat. The most likely scenario I have seen is a player using a vehicle to try and out run the storm and get inside the circle. Spending some time at the edge of the circle may increase your chances of running into a player in a vehicle.

It is worth noting that when you start to shoot a player in a vehicle they will likely jump out and try to shoot back at you. So pick your moment and use your most powerful weapon to maximise damage.

Good luck!