NEW YORK —  Larry David (search) and mtvU (search), MTV's college network, launched the "Curb Global Warming Sweepstakes" (search) Tuesday.

By signing up for the yearlong Stop Global Warming Virtual March on Washington, students get the chance to win David's hybrid car from his HBO series, "Curb Your Enthusiasm." (search)

Laurie David, the comedian's wife, founded the virtual march, which is an online petition urging politicians to protect the environment. Giving away her husband's car, though, was news to him.

"She didn't even tell me!" exclaimed Larry in a phone interview with The Associated Press. "She told my assistant!"

Over the phone, the Davids exhibit a dynamic similar to the one shown between David and his fictional "Curb" wife, played by Cheryl Hines.

Laurie David trumpeted the cause: "If not (the students), who? It's their tomorrow we're dealing with here. We've got to get them engaged on this issue. Students carry a lot of power."

But Larry said he wasn't exactly environmentally conscious during college.

"I was conscious of who I could possibly ask out, that's what I was conscious of," he said. "And I was there during Vietnam. If every student was like me in college, we'd still be in Vietnam."

Students can enter the sweepstakes through http://www.mtvU.com, and others may join via http://www.StopGlobalWarming.org.

The march, which includes participants Robert Kennedy Jr., Sen. John McCain (news, bio, voting record), R-Ariz., and Leonardo DiCaprio, is to conclude on Earth Day next April.

In the meantime, the story of Laurie giving away Larry's car seems like perfect fodder for a "Curb" episode.

"It's possible it could happen in the future," David acknowledges.

The fifth season of "Curb Your Enthusiasm" premieres Sept. 25 (10 p.m. ET).