What's really covered by the warranty, for example if the stitching or leather on the driver's seat starts to wear out (very common for any car after 5+ years)

What's really covered by the warranty, for example if the stitching or leather on the driver's seat starts to wear out (very common for any car after 5+ years) is that covered? I can understand the drivetrain and critical systems being covered for 8 years but wonder if they're going to get nickeled and dimed by customers expecting a perfect car after 8 years of hard use.