ABSTRACT
Automakers are likely to increase the number of models offered. One cost-effective strategy would base lower volume autos on a composite frame with interchangeable polymer-based body panels, fenders and bumpers. Plastic obviously does not rust like steel and since car buyers are keeping their vehicles for longer periods than in the 1970s and early 1980s, this advantage assumes more and more importance. Plastic parts are usually one-third cheaper to produce than metal parts in low-volume applications. The advantage dissipates, however, when volume reaches about 500,000 parts/year because steel tooling is more durable than plastic equipment. The standard instrument panel uses a foam-padded sheet steel frame, the vertical surface contains the openings where the instrument clusters, glove boxes, clocks and radios are fitted. Plastic sheets have replaced most steel sheets. Many autos now use an engineering polymer or corresponding alloy for a one piece instrument panel.
