Kevin Swindell crashes into the Turn 3 wall after contact with Drew Herring .
Pole sitter Drew Herring spins to bring out first caution at Iowa Speedway.
Hamlin will drive at Texas; Herring will drive at Phoenix and Homestead
Denny Hamlin says back feels a lot better and Drew Herring has a bright future with JGR.
Drew Herring is done for the night after hard contact with the backstretch wall.
Kyle Busch returns as only three-time event winner
Technology Countdown: Aerodynamics
Blake Shelton's moving speech, Martin Truex Jr.'s Skype drop-in among top moments