4: Plastic

The next time you're sitting inside your car, do like Dustin Hoffman's character did in "The Graduate" and think of one word: Plastics. Today's cars now use tremendous amounts of plastics in auto manufacturing. They make up about 50 percent of the construction of new cars today [source: American Chemistry Council]. It's not surprising because plastics are durable, cheap to make and can be turned into just about anything.

Your dashboard, gauges, dials, switches, air conditioner vents, door handles, floor mats, seat belts, airbags and many other parts are all made from different types of plastics.

In addition to the dashboard parts, many of the tiny parts inside the engine, such as the handle on the oil dipstick, are also made of plastic. Because of their lightweight nature, plastics are being increasingly used in body structures and in engines during automotive manufacturing.