The provision, under section 168(i)(15) of the federal tax code, allows speedways to write off their costs over seven years. Typically, such expensing occurs over a much longer period of time, from 15 to 39 years. The cost of the NASCAR tax credit to taxpayers has been estimated at some $40 million--over and above any tax incentives provided by state and local authorities.

Hollywood films also enjoy a tax incentive extension in the "fiscal cliff" deal. The 157-page bill may grow yet larger--and more lucrative for special interests--as the House adds amendments.