Buyers got $3,500 or $4,500 for their trade-in (depending on the fuel-mileage increase for the new vehicle over the old). The clunker was then destroyed. Under the program, $15.2 billion worth of vehicles were sold at nearly 19,000 car dealerships in every state.

The single most common swap: an old Ford F-150 pickup for a new F-150. Owners of that pickup were 17 times more likely to buy a new F-150 than, say, a Toyota Prius. The new pickups' EPA combined city/highway mileage ratings ranged from 15 mpg to 17 mpg, depending on the powertrain and other factors, up 1 mpg to 3 mpg over the old ones.

The data show the overall average fuel economy for the clunker trade-ins was 15.8 mpg combined rating, and the average for new vehicles purchased was 24.9 mpg.

Here are the 20 most common clunker trades (a specific old vehicle for a specific new vehicle) and the 25 dealers with the most clunker sales:

Enlarge By Carlos Osorio, AP Vehicles turned in during the cash for clunkers program in September are seen at the Riverside Auto Mall in Marquette, Mich.