A National Highway Traffic Safety Administration (NHTSA) investigation into GMC’s 2007-2008 Saturn Aura has been extended to include the 2005-2008 Pontiac G6 and the 2004-2008 Chevrolet Malibu. The NHTSA said the protective jacket around cables connecting the floor shifter lever to the transmission can become damaged from regular use. The cables could corrode and eventually weaken giving drivers inaccurate transmission readings. There have been seven reports of crashes caused by the problem, with one involving injuries. According to GM the problem affects mainly models with four-speed transmissions, the Malibu and G6 have similar shift systems as the Saturn Aura, but the problem happens far less frequently on those cars.