NSX uses old technology, most CD players back in the day did not recognize CD-RW discs, theres no reason for us to believe Honda ever updated the firmware.
Also, did you close the session on your CDRW? Meaning you can't reuse it. If you left it in a "Rewritable" state, that could be another reason why the old car system can't read it.
I have never tried a CDRW in an OEM NSX CD Changer, so I am just going off what I know about CDRWs in automotive CD decks. From an OEM aspect, my 99 GSR wouldnt play CDRWs either.