The most common phrases uttered in a car this year, according to a recent insurance company survey, were "Are we there yet," "Do you know where you are going?" and "You missed the turn."

That's probably comforting news to the makers and sellers of GPS units who believe this holiday season will propel their technology further into the consumer mainstream. Global positioning systems have doubled in sales as average prices have dropped during the past four years. The latest, and top-of-the line, versions offer real-time traffic information, weather updates and new radio channels.

"This will be the first season it's tested," said Ted Gartner, a spokesman for Garmin International Inc., a major GPS manufacturer, of the real-time traffic features. "We think people who know their cities will use it to avoid traffic tie-ups or when they commute to work. GPS isn't just GPS anymore. Traffic is the new frontier."

Garmin and others say their surveys show traffic information is the most coveted advance sought from GPS units, and several products have been launched in recent months, beamed via satellite or FM radio waves. The updates warn drivers of road closures, accidents and other problems and offer alternative routes before they get stuck behind them.

The makers and sellers say demand for the service by consumers, coupled with the demand for new gadgetry in general by holiday gift-givers, may provide a push for the newly loaded GPS units, which cost about $1,000 and come with a monthly fee.

The Consumer Electronics Association reports that 2004 factory-to-dealer sales of all kinds of electronic devices totaled $113 billion in 2004 and are expected to rise 9 percent to $123 billion this year.

Sean Wargo, the association's director of industry analysis, said MP3 music players will top the digital camera and plasma TV as the hottest seller among consumer electronics this season, but electronics in general are expected to sell well as consumers look to buy new devices and upgrade old ones.

Possibly propelling sales of GPS units and all consumer electronics more are prices, which have come down as more manufacturers mass-produce units and compete for buyers, according to makers and sellers of GPS units.

Factory sales of GPS units, both the hand-held and automobile kind, are projected to grow to 738,000 this year from 162,000 units in 2001. The average price, meanwhile, has dropped to $473 from $888 during that span.

Like radios, cassette players and compact disk players, GPS may eventually become almost standard in cars, especially as their popularity rises with positive word of mouth from users such as Charles Ripley of Davidsonville, Md.. He was recently in the market for his second GPS unit. He wanted one for his car that "has a voice interface" or one that speaks directions instead of just listing them on the screen.