Since 1961 GM
has been using Oscar, a "mannequin-like simulation tool," to assist in the ergonomic design and layout of its automotive interiors. Rendered in steel, plastic and aluminum, Oscar has 18 removable parts that can be adjusted to simulate a 108-lbs female occupant up through a 270-lbs male.
Supposedly, Oscar's dimensions are based on actual human x-rays, and have been adjusted throughout the years to represent the steadily growing average adult. Although just as bald and shiny as the iconic Academy Award statue, Oscar's name is actually derived from a similar aviation test dummy developed in the mid-1940's called Oscar Eightball.
Click the image below to watch a video from Chevy: