2 changes made a serious improvement in cabin quietness. I estimate they made a 50% reduction of road noise.
I added sound insulation to rear floor area and bulkhead behind the seats, fair reduction of road noise.
See thread:
Help: Procedure for removing floor carpet in coupe rear hatch area?
http://www.stingrayforums.com/forum/...atch-area.html
I made a partition / cargo shelf and noticed a further reduction in road noise and improvement in sound of the stereo. I think the partition blocks noise from the cargo area and directs rear speaker sound forward. Quite frankly I was surprised it made any difference as I wasn't expecting any noise reduction from this.
See thread:
Coupe rear partition and cargo shelf, Custom made (photos)
http://www.stingrayforums.com/forum/...de-photos.html