So I slapped on the Si axle back on my ex. Definately looks bigger, sound? meh, not so much I guess. Now I feel it looks too big on the back of the car. where with ex and the tip it looked too small.

Can anyone confirm that the screw for the axle back which has a little disk plate at the middle of the screw supposely be secured in between the resonator and the axle back? I didn't really look at it when I took it off, but when I put it back in, there was some violent jerks at the end before the spring was tight enough to not to move around, and I thought I broke the screw. But it looked fine to me from the side, and I'm too afraid to unscrew it to find out...

 

I just took my exhaust off, so yes, there is a plate on those bolts that is fixed to the bolt at the top of the threaded part. It's small enough that the spring could move over it, explaining the "jerks" you refered to.

 

Like I was really putting strength into it, but the spring was still loose. Then all the suddent it just went "clank" and the screw became easier to move and the spring is tight. Almost felt like I ruin the threads on it. Like I said, it looks ok, and I'm too afraid to unscrew it to see if the bolt was ok...

 

Even if you did mess them up they are pretty common to find. You could always knock off the spot welded nut behind the flange and get another bolt and nut from a hardware store. I used old valve springs when I lost a spring on my other civic. It's very likely you stripped or bent the bolt as they are not meant to be torqued down.

 

im not using the springs on my Si axleback. it rattles.

the holes dont line up exactly but the bolts still lock it in place.