I don't know what the f*** this patch did, but I cannot kill ANY Juggernaut with ANY vehicle. I had this achievement before, it was a joke in the past to kill them. Hit them with a car, hit them a second time, boom fat f*** dead. I just hit this one at least 30 times with two different cars, still standing. Hasn't taken a single bit of damage. What the f***? How can I get the achievement when the Juggernaut is immortal? I can kill him with guns and melee weapons but not a car? Seriously?
I smashed two police cars into him at least 30 times. Wrecked them both. Would knock it down, hit it on the floor, again and again and again. Posted that, went and got a pick up, hit it three times and it died. I don't know why the police car wouldn't do it, but whatever. Stupid glitched game.
Yeah, I use the back into him trick. You knock him down while going in reverse, and then just keep going. When you back up over him on the ground he instantly dies. You lose your back bumper and rear tires, but its still enough to limp back to base with if you really need that vehicle.