There's a very fast and easy way to obtain this achievement:
1 - Start "A Prophet on Wheels" mission (the 1st one on The Death Riders' region).
2 - Talk to Arturo and go to the designated spot.
3 - Call for a Monster Truck via Radio.
4 - Hit everyone you can with your vehicle.
5 - Let an enemy kill you if necessary and repeat process until you get the achievement.