There have been various complains from some customers on lighting and electrical issues on Pontiac G6. There were recalls which were made based on brake lamps which were not operating properly. The issue was caused by corrosion due to a wiring connector, which lead to various failures. The lamps would not illuminate which can lead to a crash due to lack of proper prior warning. You can have a mechanic check it out, to prevent any incident or accident if you are having issues with yours.