Motor Whirled host Dick Casper discusses design details of NASCAR tires. Enter to win a 2007 Dodge Charger SRT8 at <a class="link" rel="nofollow" href="http://www.wrigleysracing.com.">www.wrigleysracing.com.</a> (No purch. necessary. Enter by 10/1/07. Must be legal resident of the 50 U.S. & D.C., ages 18 +. Void where prohibited.)
