The government of Japan needs to boost efforts to promote low-pollution cars, according to an interim report released by a panel under the Environment Agency on Friday. There were only 29,000 low-pollution cars, such as electric, gas and hybrid engine cars, on the road as of the end of fiscal 1998 -- far below the target of 300,000 vehicles by 2000 set by a 1992 law intended to reduce nitrogen oxide concentrations in the air. The report says the higher price of clean cars and a lack of infrastructure to support them are major factors limiting their acceptance.