Code Location- When you get out of the elevator, there is a table in the room on the door to the right, press E on the item

Car Location- After finding the codes, when you walk out the front door, take a left down the street and keep walking 'till you find the farm shed. Hop the fence and there will be a pickup truck, press E on the driver side door and your friend can press E on the bed of the truck to where he/she can shoot while you're driving. Hope this can help you!