Pop the hood on any modern car, and there's a good chance you won't actually see much of the engine. Instead, you'll find a large molded piece of plastic sitting on top of it, sometimes complete with a giant manufacturer logo.
At first glance, it looks like automotive decoration. After all, engines spent decades sitting there completely exposed. So why do modern cars suddenly need a plastic lid, other than to make the engine bay look cleaner? The answer is more interesting than you might think.
