If it is not reported during the warranty then you could be on your own unless GM comes out with a "special policy" If it is on a repair order at a GM Dealership before the end of the warranty then GM has an obligation to repair it but you have to document that you tried to get them to fix it and followed up. In other words if you report it the week before it goes out of warranty and they do not fix it then you can't just wait a year and say something. You would have to put GM and the dealership on notice that it was not fixed and take the vehicle back in.