Tonneau cover

Tonneau cover (US /tʌˈnoʊ/ or UK /ˈtɒnoʊ/) describes a hard or soft cover used to protect unoccupied passenger seats in a convertible or roadster, or the cargo bed in a pickup truck. Hard tonneau covers open by a hinging or folding mechanism while soft covers open by rolling up.

The tonneau cover is used to conceal and or cover cargo. When the cover is pulled out, it keeps items out of the sun and provides extra security by keeping personal items out of sight.

A tonneau is an open rear passenger compartment, rounded like a barrel, on an automobile and, by extension, a body style incorporating such a compartment. The word is French, meaning 'cask'. Most tonneau covers were fixed in place as an optional element at purchase, but some could be removed as on the Crestmobile or the two-part (frame and cover) of the early MGB.

Early tonneaus normally had a rear-facing hinged door, but single and dual side doors were soon introduced. The first US side-door tonneau was made by Peerless, and others quickly followed. This led to the development of the modern sedan/saloon, with Cadillac manufacturing the first US production closed-body four-door car in 1910.

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