http://www.camaro5.com/forums/showthread.php?t=201166
You need to look at this thread. Tramtwo had the same problem and was able to make a video of it. After I watched the video I knew I was having the same issue. Turns out he had a rock in his bottom driver side rear control arm. I went out in my garage last night and guess what I found. A ROCK in my rear control arm!!! It was in the arm between the end and where the shock attaches.
I bet that's ur problem. Didn't you say you had a rock driveway?