Your source doesn't appear to have done a very thorough job. I picked one of the car makers at random (Toyota), and did some looking.
It appears that Toyota has donated $1.93 Million to the relief effort, which is more than both Ford and GM. In addition, Toyota funds numerous other charities.
Your source appears to be inventing statistics for the purpose of whipping up a little anti-foreign sentiment. Here is one of the articles that I found:
Toyota Announces Additional Donations to Disaster Relief Efforts, Raising Total to $1.93 Million
Employees And Dealers Make Contributions To American Red
Cross, The New York Police And Fire Widows' And Children's
Benefit Fund And The Washington Family Relief Fund
November 13, 2001 -- New York, NY -- Toyota and its North
American companies, employees and dealers, today
announced an additional $930,000 in donations to three
organizations assisting in the relief efforts for the tragic
events of September 11. The donations to the American Red
Cross; The New York Police And Fire Widows' And Children's
Benefit Fund and the Washington Family Relief Fund are in
addition to a previously announced contribution of $1 million
to the American Red Cross.
Toyota will donate $780,000 from U.S. employee and dealer
contributions and company matched funds to the American
Red Cross. All funds from Toyota's contribution to the
American Red Cross will go to support the families of
September 11 victims. In addition, the company will also
contribute funds to two local New York and Washington, D.C.
organizations that are providing support to families in their
communities who were affected by the tragedy. They are The
New York Police and Fire Widows' and Children's Benefit Fund,
which will receive $125,000; and the Washington Family Relief
Fund, which will receive $25,000. Combined with the
previously announced donation to the American Red Cross,
Toyota's total donation to U.S. relief efforts is $1,930,000.
