I've uploaded a video for anyone who needs visual cues. A couple reminders:
1) New enemies can spawn on previously traversed roads. Therefore, be sure to leave your wraith behind at a greater distance - so it doesn't get caught in some crossfire.
2) Be sure to clear all roads of wreckages (ghosts etc.) instead of running them over.
3) I highly recommend that you purchase a DAMAGE BOOST.
4) Make use of grenades whenever possible to destroy objectives.
5) Kill every single enemy before you go back to the wraith.