Holly Springs Police Chief Ken Ball told WSB-TV the idea is "a no-brainer" at a time when government budgets are tight.
Officials say the police cars won't be covered up like NASCAR race cars. Ball said they'd be relatively small, and would fit on the rear fenders. Officials also say they won't accept racy or controversial sponsors.
Ball said they hope the program raises $35,000 to $100,000 a year.
Critics said they worry about people who buy ads getting preferential treatment from police.
WSB reports that two businesses - a hospital and a window-tinting firm - have already expressed interest in buying ads.