It became much more noticeable with the new and improved clutch. Hard shifts I have to cringe. I have read the other posts about it being normal for Subaru's to have rear differentials that clunk a lil. My 2004 STi has 60K on it and I think the rear differentials ready to fall out! I jacked up the rear and put it on stands then got under it and with all my might, and my legs, kicked, pushed, pulled, shook, and beat on the rear diff and couldn't get it to budge. So it doesn't look like theres any play in it. But I imagine 370 ft/lb of torque from the engine is more then I can throw at it.
The other day I had been driving my auto truck around all day then got in my STi. I brain farted and slowed for a stop sign with it in 4th and didn't give it the clutch. I was daydreaming until the engine cut with a loud bang in the rear end. It sounded like I ran over a huge rock. I could just see my rear diff bucking widely in protest to my idiotic driving. Add more to the history, and il let you know I am hard on my STi, I drive it the way it should, and done several hard launches with it. So, is this normal? I mean, will some upgraded bushings fix all this, and can somebody yell out some brands with prices, and some install tips. While your at it, can you put it in?