so whats the loud noise from the back of the car on a fast 1-2 shift?

the rear diff bouncing against something?

I get them on fast shift using the clutch and it's worse if I'm powershifting sorda annoying! None of my previous DSM's ever did this, but it seems to be a common but normal issue.

happened on the 03 i test drove years ago, but does not happen on my g/f's 03

It's the loose mounts that hold the rear diff.

hhmm, my car starting doing this every once and than at the track. Kinda sounds like a belhousing? `

my car did it from the day i broke it in till now, i dont belive its anything to worry about unless it starts to get louder and louder

Y I have a clunk also.. but sounds more like its the tranny... Ill have to check this out now

Many Subaru's do this also on some hard shifts, my '04 STi did. My IX MR has done it as well. In both cases I believe it's (as stated above) the rear diff mounts clunking because they're soft. Replacing bushings is popular amongst the Subaru crowd, but I haven't come across anything for the Evo (haven't really been looking, either).

Mine does that too, I wonder if there's any kinda poly bushings that could be installed or a brace or something???

This Happens when you power shift.... you need to slip the clutch into 2nd when you mash....

Didn't you have a WRX? Mine did the exact same thing on a quick 1-2 shift. Try not to side step the clutch is all I can say.

I love the noise, it tells me i'm shifting fast enough .

Trust me on this. It's just the loose/soft rear diff mounts. You can buy harder mounts for it, but then do you want the mount to take the shock or the Diff itself?.
On my car if I shift too fast it will sound and FEEL like a sledge hammer hitting your back.

Mine does it too. I just started letting the clutch out slower and it won't.