I have a '04 coupe and @ 30K I changed out the pads on all 4 corners. I didn't change the rotors because they didn't feel like they had any decernible grooves. I used Carbotech pads and once broken in, the rears made a squealing noise. I took them (rears) apart and applied brake quiet lube to the back of the pads and they still make noise and dust up just like the OEMs did. My impression is that the pads are slightly touching the rotors. When their cold they don't make noise, but once warmed up, because of expansion, they squeal.
I don't know when I have to change them out again, if replacing the rotors along with new pads will solve the problem. I am wondering if the pistons are not pulling back when I let up on the brake pedal?
I've done brake jobs on other vehicles and have never had this problem before and I've never used a pad lube until I did this brake job.

 

Pad endplate "ears" are vibrating in their bracket holders. You need to apply some high temp grease in these locations (NOT ON THE PAD!)

 

I did lube them with grease. Any other ideas if this is not the problem?
I will take a look at them this weekend and relube them. Interesting the fronts I have no problem with whatsoever, but the backs I do. Its like the rear brakes are touching all the time, and they squeak only when you are creeping. If this is all about vibration causing this noise, just how much vibration can you be making creaping along to park in your garage? At high speed you can hear them cherping until when you hit the brake pedal then they stop for the moment.
So, I end up with dirty back wheels, while the fronts stay clean, the opposite of what you normally see on the street.