After completing the Resupply the Watch Tower job, talk to the Sheriff to start this one. Head out to the Wasteland and follow the mini-map and enter the Shrouded Bunker. Take out all the enemies in the main area, then drive an RC Bomb Car through the hole in the wall and blow it up when you get to the explosives.
Then take out the enemies in the next room and head down the elevator. In the room with a lock on it is a Authority Machine Gun, if you have a lock grinder. Eventually you'll walk through a sewer pipe. Kill everyone in the next room. Downstairs is a key card for the red door upstairs. In the next room clear out all the enemies and pick up all the parts. Then you'll need to drive the RC Bomb Car through the hole in the wall under the stairs and blow up the explosives.
Head through to the next room and take out the enemies. You'll begin to notice that you're back tracking. You'll come to a pretty tough area with an enemy on a turret. After you take him out, the door below him will open and more enemies including an extra tough one will come out. Clear out all the enemies through that door. Then take and RC Bomb Car to the hole on the right side and blow the last set of explosives. Go through the hole and take the elevator to the surface to get the Debunked achievement. Return to the Sheriff to complete the job.
As soon as you start the job, you'll be given the RC Bomb Car Schematic.
Collector Card: RC Bomb Car - Above the hole you drive the RC Bomb Car through on the left.
Collector Card: Shrouded AR - When you get to the lower area, its down the ramp in the back right corner.
Collector Card: Shrouded Heavy - After you come out of the sewer pipe, it's ahead to the right in the smaller sewer pipe that's laying out.