Movie actor Leonardo DiCaprio is giving a lift to struggling battery-car start-up Fisker Automotive. The star, who has helped promote the Toyota Prius, now owns one of the $102,000 Fisker Karma plug-ins -- and has invested in the California-based firm. But DiCaprio plans to go a step further, using his star power to promote the Fisker brand as part of a campaign for global sustainability. “My foundation supports efforts to secure a sustainable future for our planet and all its inhabitants,” says DiCaprio. “I am delighted to be working with Fisker Automotive to promote this shared vision.”