I've put up some 1/4 inch peg board in the stair well to my storage room in the attic. The stair well is pretty long as the ceiling is 12 feet tall. I put as many car parts as I can so at least I can see them. You may have guess, my storage room is full of car parts as well. I have three sets of stacked tool boxes as well for parts. I did sheet rock the room and have AC up there as well. I'm putting peg board in my mechanical room for more storage.
