sentences:  It was the first Indy 500 where all entries utilized the Dallara IR5 chassis after Phil Giebler failed to qualify with Panoz chassis - effectively ushering in a four-year "spec" era.In addition, all full-time entries began utilizing semi-automatic paddle shifters in 2008.Paddle shifters for part-time Indy 500-only entries were optional due to cost reasons.