While there is no question that Obama's Cash-for-Clunkers program accelerated vehicle sales this summer, a new report by the University of Michigan's Transportation Research Institute shows the big winners were from Japan, not Detroit.

According to the study, nearly 85 percent of the trade-ins were from General Motors, Ford, and Chrysler, yet they only sold 39 percent of the new cars moved off the lots. On the other hand, 8 percent of the trade-ins came from Toyota, Honda, and Nissan, manufacturers who accounted for 41 percent of new car purchases.

While these numbers may be justified by the large quantity of inefficient domestic trucks and SUVs that were deemed clunkers, customer loyalty also seems to have taken a big shift. About 68 percent of owners who traded in Toyota, Honda, or Nissan vehicles replaced them with another from one of those Japanese brands, while only 43 percent of consumers who traded in Detroit steel purchased another General Motors, Ford, or Chrysler product. The program cost the U.S. taxpayers about $3 billion.

[Source: USA Today | Image: Justin Sullivan/Getty]