Are most car seat covers one size fits all?

No, most car seat covers are *not* one-size-fits-all. While some are advertised as such, they often only fit a limited range of seat sizes and shapes. A truly universal fit is rare. Many covers are designed for specific car makes, models, or even seat types (bucket seats vs. bench seats). It's always best to check the manufacturer's specifications to ensure a proper fit for your vehicle.