American Hybrid Tax Credit Act of 2005 - Amends the Internal Revenue Code to increase by $3,000 the allowable amount of the tax credit for alternative motor vehicles (i.e., qualified fuel cell vehicles, advanced lean burn technology motor vehicles, hybrid vehicles, and alternative fuel motor vehicles) which are assembled in the United States.
Allows a 20% increase in the tax credit for increasing research activities for U.S.-based research on alternative motor vehicle technology. Makes such credit refundable for certain small businesses.