I have been told that I have to use BMW brake pads or I will have noise. True?
on 2004 BMW 325i

Does it really make a difference buying the original parts?

Asked by for the 2004 BMW 325i
yes the newer model like yours it will make noises if rotors and pads are not OEM but 80's model its okay i installed some of those autozone brake pads.
Why would this matter? Just wondering. I have used other routers but not pads.
Different 'blends' of materials used for different types of application/performance levels-to put it extremely simple. If rotors were engineered for use with ceramic pads and semi-metallic or organic pads are used you will likely have a difference in stopping performance and pad/rotor life , and problems with rotors warping etc.