a cardboard work mat has a pleated configuration , wherein the mat is folded in pleats for storage , and an unfolded configuration , wherein the mat defines a surface area sufficiently large for supporting a mechanic beneath a vehicle . a headrest is formed on one end of the mat by folding over the two or three end - most pleats together and then bonding them together . in an alternate embodiment , the mat is a flexible plastic sheet which has a rolled configuration for storage and an unrolled configuration for supporting a mechanic on the sheet . a headrest is molded or attached to one end of the sheet . yet again , the pad can be a pleated corrugated plastic pad having a head rest removably attached thereto by hook and eye fasteners .