Brake parts cleaner and clean your pads out, your rotors, and the inside of your calipers. I bet their nasty dirty. A bit of copper grease on the backs helps a bit too, but don't put much - you only need a thin spread of it around where the pistons touch.
My rear brake squeaks on my 04 1K - 2000 miles on it. When I had it up on the rear stand i spun the wheel (by hand of course) and the disc is warped. I could see side to side movement. Does the dealer turn these things true? Or will I have to buy aftermarket and will they be true with no squeaky. I'm going to steel lines soon so that will be the time to upgrade.