 same problem here
I have 30k miles on mine and the rear pads are gone and the rotors are too thin to be turned. I am beginning to wonder if there is something wrong with the design. The dealer was no help and said that brakes arent covered under the "bumper to bumper" warranty. So I got the new rotors and pads but I cannot get the piston to compress at all . I have tried turning it with a special tool, compressing it with a c clamp but it will not compress enough to put the new pads on. I even tried bleeding it a little bit to relieve some of the pressure but nothing worked.
I am searching everywhere on the net and trying to talk to different people to figure it out but this one has got me stumped. If anyone has the secret please let me know. I will post the answer here if I figure it out.
Thanks,
Robert | 
