Yo-yo financing is what happens when you drive off the lot with your newly purchased car, only to be reeled back in days or weeks later by the dealer because the financing didn't go through.

Your choice: Return the car or keep it and accept less-favorable financing terms. And by that time, your trade-in might be gone.

It's unclear how often this happens. A new report by the Center for Responsible Lending suggests it's not uncommon. The nonprofit polled five national organizations serving more than 2,100 consumers with auto-finance complaints. Of those, 27 percent were victims of yo-yo financing.

"The real crux of the findings here is that this really is happening, more so with people who can least afford to be caught up in this type of scam," says Delvin Davis, the report's author.

I wrote about the problem last year when the Federal Trade Commission, which oversees dealers, held meetings on auto financing, including yo-yo sales. The FTC hasn't taken any action. Then, as now, the dealer association says yo-yo financing is not an issue in Maryland. But a state regulator and consumer lawyers say it is indeed a problem here and is not getting better.

Maryland bans yo-yo financing. Once you drive off the lot with a signed contract and temporary tags, the deal is supposed to be final. Dealers also can't use supplemental agreements that say customers must return the car if the financing falls through. An exception: Consumers can be required to return a car if they provided inaccurate information on the financing application.

Davis says his report tried to find out who gets trapped by yo-yo financing and what happens to them. Among the findings:

•Victims tend to be consumers with low incomes or weak credit and few financing options.

•More than half of consumers could not recoup the down payment or trade-in vehicle. Sometimes their old vehicle had been sold.

•Dealers often charged a rental or restocking fee when the car was returned.

•A majority of consumers renegotiated terms, and more than 60 percent ended up with a higher interest rate.

Peter Kitzmiller, president of the Maryland Automobile Dealers Association, says Maryland doesn't have a yo-yo financing problem. If customers are asked to return to the dealer because of financing issues, he says, it's because they provided incorrect information, such as their length of employment.

He adds that dealers want good relations with customers and don't benefit when cars are returned.

"We're in the business of trying to sell them a car, not to have them bring cars back," Kitzmiller says.

But Mark Steinbach, a consumer lawyer in Maryland and Washington, says dealers do have an incentive to allow a customer leave with a car even though the deal is incomplete.

"They do it to control the customer, to make sure the customer doesn't go down the street to one of the competitors and buy a car from them," he says.

Steinbach says dealers that have handled thousands of transactions know which applications likely will be financed by lenders and which won't. Dealers also know that once consumers take a car home and show it to friends and family, they will do what they can to keep it, he says. Consumers often end up paying a higher interest rate or a larger down payment or finding a co-signer.

Steinbach, who receives up to 20 such cases a year, calls the practice "rampant."

"We receive complaints about this all the time," says Karen Straughn, director of the Maryland consumer protection division's mediation unit.