I've designed an overhead truck rack (CyberRack) for the Cybertruck that stores in its vault. Normally you don't see it, but when you need it, it sets up fast taking advantage of the rear sloping roof on the cab to allow for an extended front crossbar making its overall length over 100 inches...
This image from Cybertruck reveal night hasn't gotten much focus - the one circled in the first image below. Don't know why it's the only one that Tesla didn't release a large version of, but zooming in on the image (from a reveal night video) shows what looks like a ladder rack and tools...