False ads, deceptive loans and fake odometer readings are some of the charges made by the feds against some auto dealers.
An investigation led by the Federal Trade Commission and law enforcement has led to 252 enforcement actions and $2.6 million in consumer refunds and fees.
In one case, a company called the National Payment Network Inc., in San Mateo, California, pitched car buyers an automated payment program that was said to save customers money.
The investigation also found car salesmen who rolled back odometer readings, failed to disclose known defects on a car and added costly services and warranties without a customer's consent.
But regulators say undisclosed fees were so heavy that they canceled out any savings.
National Payment Network did not return a reporter's telephone calls for comment.