Say I install a set of AutoExe Member bars. Can someone with actual experience tell me how much more noise and vibration I can expect with them?

 

you mean the ones for stiffening the chassis i.e. the x brace right? if so it shouldn't make it any more noisy if anything I would think that it might cut down on noise because the chassis wouldn't be flexing as much? but it probably wont change the noise much at all if any

 

Someone's feeling rich. I don't think those rear bars will make much difference. Here's a much cheaper alternative, if you want you can make it out of aluminum too.

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/how-build-lower-arm-bar-under-%2415-448638/