As a service tech, my van is full of parts. At first I thought of clear plastic boxes to put on the racks. This works well in the summer, but living on the tundra, it is not so great when it is -20F outside and you are trying to pry open plastic covers. They either break or are difficult to get open. Those plastic storage units are spendy to replace. Here is the answer to some of my problems.
1. Cardboard box
2. 4 washers
3. 2 screws
4. 2 nuts
5. Twine or string
6. Awl or punch
7. Nail polish
First step is to find a STURDY cardboard box. You want something strong that will last a while.
Punch 4 holes on one side of flap and thread the twine through the holes and tie down.
On the other side of box punch two holes and put screw and washer on one side of flap and nut and washer on the other. Tighten the assembly so it is somewhat snug, but not extremely tight. Then apply nail polish (or locktite) to the nut and wait a few minutes to dry. This will keep the nut from coming loose. You can also apply nail polish to the twine ends to help keep from unraveling.
To close the box, pull the twine under the washer and wrap it about 2 turns around the screw. The box will open/close easy/peasy and will be quite durable to boot.