This one can be a little annoying as you do not have any way to make Elana turn passive and not kill anyone. You will need to make your way to the jeep and begin driving. Elana will be in the back shooting. You will need to do your best to drive in such a way that she cannot get a good shot. If she kills an enemy you wont be able to get the trophy. In short, this trophy requires you to play in a way that makes your AI partner useless. Making it one of the very few times in gaming history where you need to put some effort into making your AI partner suck.
Drive away in the jeep with Elena without killing any enemies