New cars that are fully loaded -- with debt - Americans are rolling over loans, often ending up owing more for the vehicle than it's worth.

The dealership, near the Posts' home in Victorville, made it easy; it just added the old debt to the price of the new truck and gave the couple a seven-year, $44,276 loan.

The Posts were a little worried about taking on such a long obligation, but they couldn't pass up a monthly payment under $700. Now they're having regrets.

"I didn't realize how much debt was in it," said Jennifer Post, who has since moved with her family to Iowa. Now, she'd like to get rid of the truck but can't, because there's so much debt that she'd literally have to pay someone to take it off her hands.

"We have no options," she said.

Americans haven't just been taking out risky mortgages for homes in the last few years; they've also been signing larger automobile loans for significantly longer terms than they used to.

As a result, people are slipping into a perpetual cycle of automobile debt that experts think could lead to a new credit crunch extending from dealerships to driveways and all the way to Wall Street.

Gone are the days of the three-year car loan. The length of the average automobile loan hit five years, four months in October, up more than six months from 2002, according to the Federal Reserve. And nearly 45% of loans written today are for longer than six years. Even some staid lenders owned by the carmakers, such as Toyota Financial Services and Ford Credit, are offering seven-year financing. And a few credit unions, particularly in the West, are tinkering with the eight-year note.

At the same time, the amount of money drivers owe on their cars is soaring. In October, the average amount financed hit $30,738, up $3,500 in just a year and nearly 40% in the last decade, according to the Fed. More troubling, today's average car owner owes $4,221 more than the vehicle is worth at the time it's sold -- up from $3,529 in 2002, according to industry analyst Edmunds.

The longer loans are directly related to the higher balances. By extending the length of loans, lenders keep monthly payments down. But because these loans take longer to pay off, a much larger piece of the principal remains unpaid at the time the car is traded in.