US hybrid sales mostly slack despite gasoline hike.

DETROIT (Reuters) - U.S. gas prices have risen nearly a third over the past year without touching off a boom in sales of fuel-efficient hybrid vehicles, some of which are sitting on dealer lots for as long as three months. Many U.S. consumers are concluding that what they save in gasoline and on tax credits from driving a hybrid does not justify the roughly $3,000 premium they face at the dealership, even with high and volatile fuel prices, analysts said.