GM is recalling 426,240 midsize sedans because the shift cable might break. That means that when you put the car into Park, it might actually end up rolling down a hill.
The cars involved in the recall are 2008-2010 Chevy Malibus, Pontiac G6s, and 2007-2010 Saturn Auras equipped with the four speed automatic transmission. The recall states that "if the tabs were to fracture and separate, the shift lever and the actual position of the transmission gear may not match."
GM will be notifying owners shortly and fixing the cars free of charge.