Squealing Breaks

Looks like semi-metallic pads were optional on your CTS, Because I see all the name brand manufacturers have ceramic and semi-metallic available, So when the brake pads need replacement have ceramic pads installed because metallic pads can be noisy and you can check pad replacement cost here https://repairpal.com/estimator/cadillac/cts and find a shop to change them here https://repairpal.com/cadillac-repair-in-jackson-mississippi