is a large sheet metal stamping
that often incorporates several smaller welded
stampings to form the floor of a large vehicle
and the position of its external and structural panels.
In the case of monocoque
designs, the floorpan is the most important metal part establishing the chassis
, body, and thus the car’s size. It serves as the foundation of most of the structural and mechanical components of a unibody automobile
to which the powertrain
, suspension system, and other parts are attached.
The term is also applied to the smaller stamped panels that form the floors inside a vehicle as well as the bottom of the trunk.