sentences:  In an unusual move, CART "sanctioned" the participation of teams in the race; This was an attempt to allow Penske's primary sponsor, Marlboro, to appear on cars in the 500 as they were prohibited from being in more than one racing series by the Tobacco Master Settlement Agreement.This legal maneuver was not successful, and Penske's cars ran without advertising.The following teams and drivers competed in the 2001 CART Championship Series season.