I just installed the GD subframe spacers no more then a month ago. Immediately after I started driving it, I noticed the driveshaft "clunk" as well. Assuming it was the center support bearing going bad, I'm skeptical after reading this post. Yugo posted that it could be the diff. bushings. If this is true, how can you test this? I am read to either replace the center support or get a 1 piece from Z1 or take out the spacers and see what happens. The clunk is annoying and happens when I hit the throttle and let off and the car has to be going about 25-30mph or over.