i happened to look at a S2000 this weekend, and noticed the S2000 has different looking bushings on the top shock mount. #6 probably stiffer. i checked the part number, and it looks like the mounts are the same as the civics/integras, so the bushing is probably interchangeable.



this is just head knowledge. i dont think anyone else cares...

further head knowledge is that integra type r comes with much stiffer bushings too, which are only $10 each. theyre half metal, half rubber, and fit other civic and integra shock mounts. these s2000 ones are $20 each.

 

Both the ITR and the S2000 have the steel sleeve (#14 above) bonded solidly into the rubbers (#6) and is not removable unlike most of the predecessing Honda and Acura cars where the sleeve #14 is removable as shown in the photo.

I cannot confirm nor deny that the durometer of the rubbers is harder on the S2000 and ITR but is wouldn't surprise me if it was a little bit.