J
<Jonlisle20>
I'm not sure if any of you have/had this problem, or even if any of you solved it already, but if you are hearing a "clunk" sound from the rear of your MP3, it is caused by over-sized stabilizer bushings. Some other people over at the MP3 Yahoo! Group were having this problem as well. The bushings are actually too big for the rear stabilizer. It would actually slap around inside them, creating the BANG or CLUNK sound. My dealership didn't replace my bushings, but they did "shimey and re-clamp" them (apparently pressing them tighter to the stabilizer bar) which has caused the clunk sound to disapear. Unfortunately, the noise may return after a while due to the fact that the bushings are still too big. To address this problem, they have placed a call to Mazda and will get back to me when they hear something. (Soon I hope!) Hope this helps alleviate some frustration! 
