Deletes everything. Amends the Illinois Income Tax Act. Repeals a Section concerning the Transportation Employee Credit. Amends the Use Tax Act, the Service Use Tax Act, the Service Occupation Tax Act, and the Retailers' Occupation Tax Act. Provides that, beginning July 1, 2004 and through June 30, 2005, the use in this State of certain motor vehicles of the second division that are primarily used for commercial purposes is exempt from the taxes imposed by those Acts. Defines "used for commercial purposes". Beginning July 1, 2004, defines "rolling stock moving in interstate commerce" to mean, for certain motor vehicles and trailers, when, during a 12-month period the rolling stock has carried persons or property for hire in interstate commerce for greater than 50% of its total trips for that period or for greater than 50% of its total miles for that period. Authorizes the person claiming the exemption to elect at the time of purchase whether to use the trip or mileage method for determining eligibility for the exemption. Sets forth procedures for determining the number of qualifying trips or miles for motor vehicles and for trailers. Provides that the exemption for rolling stock moving in interstate commerce applies only for motor vehicles whose gross vehicle weight rating exceeds 16,000 pounds. Provides that the definition of "rolling stock moving in interstate commerce" applies to all property purchased for the purpose of being attached to the rolling stock. Amends the Illinois Vehicle Code. Provides that the amount of taxes and fees incurred under certain provisions of the Illinois Vehicle Code shall be equal to: (i) 36% for a registration year beginning on or after July 1, 2003 and before July 1, 2005; (ii) 21.5% for a registration year beginning on or after July 1, 2005 and before July 1, 2006; and (iii) 14.35% for a registration year beginning on or after July 1, 2006. Effective July 1, 2004.