This is an excerpt from a Canadian GM dealer's website regarding bumper to bumper warranty
A vehicle can have over 13,000 parts so, as you can tell, a lot more is actually covered by your warranty than not! However, you should note that items with daily wear and tear are generally not part of the overall warranty, such as:
Regular, all-season or winter tires
Standard maintenance items like oil, filters, wiper blades, transmission fluids, sparkplugs, lightbulbs, batteries, etc.
Brake pads and related friction materials that wear down with use
Clutch wear components
Windshields, glass and mirrors
Shock absorbers and struts