Creeper

Like a luge, only for concrete rather than ice, and for lying still rather than going fast.

Lie on your back on the creeper so you can roll around under a vehicle rather than awkwardly shimmying across the cold, dirty ground. Please don't try to roll on rough bitumen or over uneven seams between concrete slabs, as the castor wheels can be damaged by this. If it takes more than a gentle push to roll yourself, get off the creeper before moving it.