Greg Signore, owner of Elm Auto Sales, is pictured Tuesday at his used-car business in Kearny, N.J. Under Cash for Clunkers, old gas guzzlers turned in at the new-car dealership are rendered inoperable and towed to the salvage yard. By some estimates, three of every five of those cars would have normally gone to a used-car lot for resale.

Richmond, Va. ? One man’s clunker is another man’s meal ticket.

Mom and Pop used-car dealers are feeling the crunch as the old Caravans and Cherokees that provide their livelihood get traded in and banished to junkyards under Cash for Clunkers. By some estimates, three of every five of the used cars turned in for government rebates would have ended up on used car lots or resold for parts.

While the Clunkers program helped push sales of new cars in July to the highest level in nearly a year, sales of used cars have taken a beating.

“We’re struggling and a lot of us small guys are going out of business,” said James Dameron, sales and finance manager at Chase Motors in suburban Richmond, where sales are down about 30 percent.

About 40 million used vehicles are sold a year, four times the number of new cars, said Keith Whann, an industry expert and chief executive of Columbus Fair Auto Auction in Columbus, Ohio. About a third of the used sales come from independent dealers.

Mom and Pop dealers typically sell just 20 to 25 vehicles a month and keep 40 to 45 vehicles on their lots, a fraction of the inventory for bigger dealerships, Whann said. So when the owner of a 1995 Ford Explorer opts for a new car, and the old SUV goes away forever, the repercussions are felt quickly. Especially for a majority of these dealers who have fewer than six employees.

Even before the clunkers program, the market for used cars was the worst it’s been in years.

Fluctuation in gas prices and higher prices at car auctions, where used car dealers get most of their supply, made the market volatile. Customers held onto older cars longer, making it more difficult to get trade-ins to beef up inventory.

To meet the environmental goals of the program, the old cars must be taken off the road. Their engines are choked with liquid glass and the guzzlers are carted off to be flattened.

About 60 percent of the cars traded in under the clunkers program would have ended up resold on used lots or at auctions, Whann said. If, as expected, 750,000 vehicles are traded in under Cash for Clunkers, that’s 450,000 cars and trucks that won’t make it to the used-car market.