At least four of the country's top rental car firms sell information on their customers to a photo enforcement firm. American Traffic Solutions and its subsidiary, ATS Processing Services, signed contracts through which Avis, Budget, Hertz and Advantage agreed to hand over information on renters so that ATS can collect extra money on photo tickets.

A California motorist, who asked to remain anonymous, found this out the hard way when his rented Toyota was accused on August 24, 2009 of traveling at 55 MPH on Interstate 295/395 near 9th Street in Washington, DC. The limit at this freeway location is just 40 MPH. Even though the driver believed the $50 ticket was issued in error, his credit card was automatically billed $30 pursuant to the small print in his rental car contract. The driver learned that the District's photo radar tickets were not valid when two vehicles are visible in the violation photo and decided to contest the fine by written declaration. He won.

"The examiner determined that the ticket should be dismissed for one of the following reasons: there was an error on the ticket, the government was unable to establish the violation or the evidence submitted was sufficient to prove a defense to the violation," the District Department of Motor Vehicles examiner ruled on May 16.

Despite the victory on the $50 ticket, the motorist now had to fight ATS to get his $30 "processing fee" back. Frequent business travelers who rent cars complain that they are often billed in error for photo tickets, parking tickets and toll road tickets that pass through ATS.

"They are hoping that a large number of people won't even notice the $30 charge, or will simply accept it," one user of the flyertalk.com forum wrote last year. "Then, by making it so onerous to get the charge reversed they hope more people will just give up. They hire minimal customer service staff, so their costs must be next to nothing. It doesn't take many $30 charges to turn a tidy profit."

ATS defends the $30 fee by claiming it covers a number of real costs associated with processing all municipal violations issued to the rental car company.

"The administration fee covers the cost associated with data entering each citation document, identifying the renter of the vehicle at the time the violation occurred, printing and bank fees incurred with billing and collecting fine amounts from renters, as well as the administrative costs of writing and mailing checks to ticket issuers before the citation due date," the ATS website explains.

In the case of Washington, DC, ATS also happens to be the "ticket issuer" -- the company that runs the photo radar program -- meaning the firm collects $80 instead of just $50 from every Avis, Budget, Hertz or Advantage customer photographed. ATS insisted that its rental ticket program is fair and operated above board.

"Our refund procedures are very simple and expedient when a renter shows evidence that a violation has been dismissed," ATS spokesman Sherri K. Teille said in an emailed response. "If the renter is unable to provide proof that a violation has been dismissed, ATS will contact the ticket issuer or municipality to verify dismissal so that the renter does not have to do so. Our call center is adequately staffed, as evidenced by consistently low call abandon rates and fast average speed of answer."