NASCAR recently told teams to increase the rear window fins from 1.5 inches to 2.5 inches for the Pepsi 400 July 5 at Daytona. While officials were researching the possibility of adding a third roof flap to the cars for restrictor-plate races, they discovered that adding an inch to the fins improved the efficiency of the two existing flaps. NASCAR still is working on adding a third flap, but for now the larger fins should make the cars more stable.( Sporting News )(6-23-2003)
