Within the next week, the greatest minds of the advertising world will unleash their latest creations for this year's Super Bowl, and as always several automakers will spend millions of dollars attempting to lure a few eyeballs away from the snack table for 30 seconds. Yet the U.S. government's consumer watchdog has sent a new warning to the industry's ad masters: If you're going to show off a car, think big — or don't do it at all.

The U.S. Federal Trade Commission announced Thursday it had settled a complaint with Nissan and ad agency TBWA over a TV spot for the Nissan Frontier pickup that showed it pushing a dune buggy up a steep sand dune. Despite the disclaimer "Fictionalization: Do not attempt" at the beginning of the ad, the agency complained that Nissan was misleading potential Frontier owners about the truck's powers.

According to the FTC:

In fact, the truck is not capable of pushing the dune buggy up and over the hill, and both the truck and the dune buggy were dragged to the top of the hill by cables, according to the complaints. The complaints also allege that the hill was made to look significantly steeper than it actually was. “Special effects in ads can be entertaining, but advertisers can’t use them to misrepresent what a product can do,” said Jessica Rich, Director of the FTC’s Bureau of Consumer Protection. “This ad made the Nissan Frontier appear capable of doing something it can’t do.”

To the FTC, the disclaimer also did not do enough to offset the cinema verite style of filming that made it seem like Nissan had grabbed the images from a YouTube spot. Think about that: It's not just what the ad says that runs afoul of the truth squad, but how it does so. If Nissan had made it more outlandish, and filmed it in the style of a more traditional car ad, apparently that would have been OK.

Even taking into account P.T. Barnum's old axiom about the birthrate of suckers, this seems like a stretch. The FTC's ruling sprung from within the agency, not from a consumer complaint; did any owners of the 62,357 Nissan Frontiers sold last year actually expect to clamber up a dune in one? The FTC's ruling doesn't offer a clear prescription of what's considered in and out of bounds. What about this Nissan Rogue ad where it jumps on a moving train? And what of this airborne Ford Fusion ad? Will the FTC protect people who might suddenly fling their midsize sedans and SUVs off cliffs in the mistaken belief they have the power of flight?

It's also notable that the FTC didn't play a role in more serious cases of misleading advertising from automakers over the past couple of years, namely when companies touted fuel economy ratings on several models that were later found to be inflated. To police the truth in advertising beat, it's helps to know what the truth is. Deciding whether they're too entertaining or outlandish sounds like a ruling best delivered over the Doritos bowl.