I just had my original clutch replaced in my '03 WRX sedan at 131K. Because I waited so long the flywheel could not be resurfaced and had a nice groove in it. Also, my mechanic discovered that the U joints on the prop shaft were really worn, so I had that replaced.
I got the Exedy OEM replacement clutch from Amazon for $146.50 free shipping, the OEM Flywheel came from the stealership for $280
- because I didn't know I would need it for sure- and the rebuild of the prop shaft u joints cost $490 plus $750 labor for the whole thing.
At this point I started hearing the noise exactly as described in this amazingly old thread. Only on deceleration while in gear. Clutch in - gone. Neutral - gone.
I never used to have it so I was worried that there was something going on with the new clutch. I am definitely glad to hear it is most likely nothing and I will check the bracket mentioned above to see if it was bent.
How much effort is it to replace it? Just looks like a few bolts.
Also, just before I replaced all of the above, I noticed a gear whine when the car was cold and when I was accelerating while turning. That has not gone away after all that work and now I need to track down what that could be.