Silent-running electric cars sneak up on you on street corners and parking lots. Are they also creeping up on a U.S. car market? Some industry analysts think so. While headlines have been blaring bad news about electric vehicles, they say, EVs have been making quiet progress. There have been strides made, they say, in battery technology, infrastructure and consumer confidence. And, they add, EVs are showing up in company fleets, and electric cars with gas-power backup -- known as plug-in hybrids -- are exceeding expectations.