When you are supposed to flee from other cars shooting at you, look for big open spaces like the Staples Center parking lot and drive through them. The people chasing you will stay on the road and go all the way around, giving you a good chance to escape. To escape easily while in pursuit, drive to the nearest highway. Try to get a good lead from the enemies before you do this. Drive up the branch of the highway, and keep straight. Do not leave the highway. Enemies are not able to get on the highway when you do this. They stick to the main road. Keep straight and eventually you will gain your points and end the mission.