Signing up with Zipcar will allow you to spend more time having sex and less time parking your car.

That’s the idea expressed in a new outdoor execution from Boston’s eFlicks Media. It reads: “350 hours/year having sex. 420 looking for parking. What’s wrong with this picture?” Another ad begins, “The car for people who don’t want one.” The effort closes with the “Wheels when you want them” tagline.

Since breaking a few weeks ago, the ads have “already created a real buzz. We’re a small company without a lot of resources, so something that gets people talking is what we want to do,” said Nancy Rosensweig, director of marketing at Cambridge, Mass.-based Zipcar. Although Rosensweig has gotten a few calls from parents who don’t want their children to read the work, the feedback has been mostly positive.

“People love it—they try to do the math and it’s been posted all over the Web,” said Rosensweig.

Ads are running on bus shelters, subway stations and urban panels in Boston, Washington, D.C., and New York, the markets currently served by Zipcar.

The client has about 2,000 customers. Members pay a $75 annual fee, then rent cars on a daily or hourly basis.