Tax Incentives for Fuel Efficient Vehicles Act of 2003 - Amends the Internal Revenue Code with respect to the (automotive) gas guzzler manufacturer excise tax to: (1) increase the weight of a covered automobile to12,000 pounds; (2) revise the excise tax table, including the addition of a model-year calculation criteria; (3) revise the exception to such coverage, including elimination of the exception based upon nonpassenger treatment under specified Department of Transportation rules; and (4) apply such provisions to sales after October 31, 2005.Establishes a highly fuel-efficient automobile credit for taxpayer purchases of a new passenger or nonpassenger automobile (as defined by this Act) that exceeds specified fuel economy ratings. Applies such credit to vehicles placed in service after October 31, 2005.