Brake problems

[Dream240]

I have the 300zx brake upgrade all the way around and I'm running into warped rotors!! I just replaced the rear rotors, which were cheap ebay rotors, with Brembo blanks. The heavy vibration I had at highs speed braking disappeared instantly. So I knew that was the problem. Well, about three days ago my brakes started sqeaking out of nowhere, WTF? I figured they were just dirty, so i washed the car and sprayed down the brakes with the hose. ALOT of black crap came off the wheels and brakes. Squeak was gone. Then yesterday I started to notice the high speed vibration under braking again!! So WTF I warped them already? It's only been a couple weeks!! I broke them in like i was supposed to, easy braking under the first 500 miles. I'm at a loss, the only thing I can think of is maybe my brake bais is screwed up? I have swapped out the MC with the 17/16" Z32 and I have the SS brake lines. What else could be causing this problem? I know it's the rear brakes cause the vibration shakes the whole car and not the steering wheel that much. you can feel it in the steering wheel but only from the car shaking. And it's groans from the rear somewhere when I brake. ANYONE HELP!!! I'M READY TO BLOW MY CAR UP!!!!