Novadrome

I managed to get this achievement in one try so I'm hoping this achievement isn't too difficult for anyone else to unlock. Survivor mode won't unlock until after you're done with the Rookie levels in single-player. Survivor is basically Last Man Standing; everyone has one life. However, everyone's health also drains and the only healing items come from dead enemies.

First things first: make sure you're in Arcade Challenge and not story or Free Play. Select any map (I usually just stick with the first map given) and then choose Iron as your character (violet pick-up truck. Stats are 1 DEF and 2 POW, if I remember correctly). This vehicle does a huge amount of damage while ramming into other vehicles head-on. You'll need to do this to kill your foes easily. Also, this character can absorb a bit of damage.

From what I recall, there were actually repair kits in the levels still, so I was able to keep my health up even if there weren't any enemies. Killing them should be easy enough. When you're down to just 2 or so opponents, they tend to drive off in other directions. Kill them ASAP. When you get your last kill, you'll automatically get a health bonus. Hopefully it is enough to put you back at maximum (again, you shouldn't have lost too much health with Iron).