In character, the used-car dealer is a close cousin to the Web spammer, so he appreciates the advantages of misleadingly labeling a car ad as porn in order to drive up views, which is what Massachusetts-based Clay Corp. did with a YouTube video titled "Let's Get Naked." Expect much, much more of this to come: There are 20,800 car dealerships in the U.S., and one in four use Web videos to market themselves, reports Ad Age . In 2006, General Motors stopped marketing its used cars anywhere but online. GM marketer Larry Pryg says car dealers made the move because Web video is often free to distribute and even cheaper to make than your average BUY! BUY! BUY! NOW! NOW! NOW! local car-dealer commercial. Clay Corp's deceptive video: Can you spot the one that doesn't belong?