Make your way through the level until you enter the sewers. Once you have found the ladder to make your way out you will be under a freeway with several cars around you. Do not attempt to jump on any of the cars that have flashing lights. As soon as you exit the sewer you will see two white cars in front of you. Jump onto the white car and then make a dash for the other end of the impound lot. As long as you don't shoot the cars or set of any alarms in this area, the achievement will unlock once you get to the safe room.