Falling gas prices and more aggressive discounting by some automakers have helped June car sales inch upward from the decline in May, according to analysts. The pace remains weaker than in the first quarter, primarily due to the earthquake and tsunami in Japan this past March, which damaged several assembly and parts plants, delaying production of more than 500,000 vehicles. The lack of new product, for the most part, hit dealerships in May and June. Manufacturers are now ramping up production to make up for the loss. New vehicle sales in the second half of the year will rise as consumers begin to replace old cars and trucks, according to Paul Taylor, chief economist for the National Automobile Dealers Association. Also helping boost sales are lower gasoline prices and a wider availability of consumer credit.