SACRAMENTO – California motorists have a new incentive for buying low-emission, plug-in hybrid cars.Gov. Jerry Brown on Wednesday signed into law Assembly Bill 95. The legislation, first conceived by Sen. Fran Pavley (D-Agoura Hills), expands to 85,000 from a current 70,000 the number of vehicles eligible to carry a so-called green sticker.The sticker allows drivers of such low-polluting cars to use carpool or “HOV” lanes, even if they carry no passengers. The measure takes effect July 1.