In the left part of the building on the counter, you can find 13 Parts, as well as supplies spread throughout. Head to the left of this van into the building you saw the Rattlers come out of. Interact with it to get the final Journal Entry of the game. When they’re dealt with go up the tracks to where you can find a green van with a Rattlers logo painted on it. Watch for enemies here as there are ones that now start having helmets on, so they can’t do killed with one headshot from your guns.
Watch for enemies as you get near as there will be more that wander out of it and start patrolling in front, along with more to the left and another dog. Search the inside of this first building for supplies, then make your way towards the second building.