DETROIT // The "cash for clunkers" programme has been embraced in the US, but there has been a downside: car buyers may not find their preferred colours or accessories. Carmakers could need up to six weeks to rebuild supplies, said John McEleney, the chairman of the National Automobile Dealers Association. He said General Motors and Chrysler dealers could be most affected after slashing production during bankruptcy. "With this quick spike in sales, it has wiped out a lot of inventory," said McEleney, who owns dealerships in Iowa. "The selection won't be quite as great."