All my rear suspension bushes are shot and rather than replace each bush i just got all the tbsti gear with the alloy arms and knuckles to swap in. I didn't consider the nvh until I noticed the below note on noise from Subaru
Running frequent interstate trips I have already added deadening to quieten things down, I figure it can't make too much difference as the sub frame is still rubber damped but I might not bother with the lateral arms and just replace the oem rubber bushes if it's too noticeable
